International Islamic University Malaysia Kulliyyah Of Dentistry

INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA KULLIYYAH OF DENTISTRY

MANUAL FOR OPERATIVE DENTISTRY (PHASE 1: YEAR 2) PART 1 BACHELOR OF DENTAL SCIENCE

PREPARED BY: Dr. Shawfekar Hj Abdul Hamid BDS, BEd, MSc, MDSc KOD IIUM

LIST OF CONTENTS 1.

Fundamentals of cavity preparation. 5

1.1 Introduction. 5 1.2 Objective of cavity preparation. 5 1.3 Definition of cavity preparation. 5 1.4 Principle of cavity preparation and lining. 5 1.4.1 Principle of tooth preparation. 5 1.4.2 Cavity preparation terminology and abbreviation. 6 1.4.3 Preparation of lining. 6 1.5 Cavity classification, location, and description. 7 1.5.1 Cavity classification. 7 1.5.2 Cavity location, and description. 11 1.6 Procedure in cavity preparation. 14 1.6.1 Cavity preparation walls. 14 1.6.2 Cavity preparation floor. 15 1.6.3 Cavity preparation angles 16. 1.6.4 Cavity preparation point angles. 16

2.

Moisture control and tooth isolation. 18

2.1 Mouth Rinsing: 18 2.1.1 Performing a mouth rinse. 18 2.2 Oral Evacuation Method: 19 2.2.1 Saliva ejector 19 2.2.2 High-Volume oral Evacuator 20 2.2.3 Positioning the High-Volume Evacuator during a procedure 23 2.3 2.3.1 2.3.2 2.3.3 2.3.4

Isolation techniques: 24 Cotton rolls 24 Cotton rolls placement 25 Related aids 25 Placement and removal of cotton rolls 27

2.4 Rubber dam isolation: 28 2.4.1 Dental dam equipment 29 2.4.2 Preparation of dental dam application 32 2.4.3 Preparation, placement, and removal of dental dam. 34 3.

Caries excavation and temporary restoration. 39

3.1 Access cavity and caries excavation. 39 3.1.1 The establishment of outline form. 39 3.1.2 The establishment of resistance form. 40 3.1.3 The establishment of retention form. 41 3.1.4 Convenience form. 41 3.1.5 The treatment of residual caries. 41 3.1.6 Finishing of enamel walls and cavo-surface margins. 42 3.1.7 The toilet of the cavity or cleaning of cavity. 42 3.2 Temporary restoration. 43 3.2.1 Introduction. 43 3.2.2 Note on principles of caries excavation. 43 3.2.3 Temporary restoration with Zinc Oxide and Eugenol. 3.2.4 Temporary restoration with GIC (Fuji VII). 46 3.2.5 Temporary restoration with Zinc Phosphate. 47 3.2.6 Temporary restoration with Gutta-Percha. 48

44

4.

Preventive resin restoration. 51

4.1 4.2 4.3

Fissure sealant. 51 Pit restoration with composite. 54 Pit restoration with GIC (Ketac Molar). 56

5.

Acid-Etch Techniques and Abrasion Cavity Restoration. 58

5.1 5.2 6. 6.1 6.2

Acid-etch technique. 58 Abrasion cavity restoration. 59 Amalgam restoration. 60 Amalgam restoration materials. 61 Class I amalgam restoration 62

6.3 6.4 7. 7.1 7.2 7.3 7.4

Class II small and medium amalgam restoration. 100 Class V amalgam restoration. 130 Composite restoration. 133 Composite restoration materials. 136 Class III composite restoration. 137 Class IV composite restoration. 154 Class V composite restoration. 167

1. FUNDAMENTALS OF CAVITY PREPARATION. 1.1 Introduction: Cavity preparation is the mechanical alternation of defective, injured or diseased tooth in order to best receive a restorative material that will reestablish a healthy state for the tooth including esthetic correction when indicated, along with normal from and function. Teeth needs for restoration are variety of reasons as follow:

• • • •

To To To To

restore the integrity of the tooth surface. restore the function of the tooth. restore the appearance of the tooth. remove the diseased tissue from the tooth.

1.2 Objectives of cavity preparation: The objectives of general cavity preparation are: • To remove diseased tissue as necessary and at the same time provides the protection to the pulp. • To locate the margins of the restoration as conservative as possible. • To ensure the cavity form, it should be under the force of mastication of the tooth or the restoration or booth will not fracture and restoration should not be displaced. • To allow the restorative material and functional placement. 1.3 Definition of cavity preparation: Cavity preparation is the mechanical alternation of a tooth to receive a restorative material, which will return the tooth to proper anatomical form, function, and esthetics. The procedure of the preparing the tooth is the removal of the defective or friable tooth structure. Any remaining infected or friable tooth structure may result of further carious progression, sensitivity or pain or fracture of the tooth and / restoration. 1.4 Principle of cavity preparation and lining: 1.4.1 Principles of tooth preparation. Gain access to caries. Remove all caries. Cut away all significantly unsupported enamel. Extended margins so that they are accessible for instrumentation and cleaning. Why restore? To restore function. To prevent further spread of an active lesion, this is not amenable to preventive measures. To prevent pulp vitality. To restore aesthetics. 1.4.2 Cavity preparation terminology and abbreviation. Simple cavity: Preparation involving one surface of the tooth. Compound cavity: Preparation involving two surfaces of the tooth. Complex cavity: Preparation involving three or more surfaces of the tooth. For record and communication, the description of a cavity preparation is abbreviated by using the first latter, capitalized, of each tooth surface involved. Examples are (1) An occlusal cavity is an O. (2) A preparation involving the mesial and occlusal surfaces is a MO. (3) A preparation involving the distal and occlusal surfaces is a DO. (4) A preparation involving the mesial, occlusal and distal surfaces is a MOD. Abbreviations for simple, compound, and complex cavities: MOD: :Mesio-occlusal-distal DO: :Disto-occlsal MO: :Mesio-occlusal MI: :Mesio-incisal

DI: :Disto-incisal LI: :Linguo-incisal DL: :Disto-lingual MODBL: :Mesio-occluso-disto-bucco-lingual I=incisal, M=Mesial, D=Distal, B=Buccal, O=Occlusal 1.4.3 Preparation of Lining. Although the placement of cavity liners and base is not a step in cavity preparation, it is a step in adapting the preparation for receiving the final restorative material. The used of air-water spray coolant in high-speed rotary instrument also protects the pulp as it dissipates the heat generated during cavity preparation. The use of lining/liner or base in cavity preparation becomes essential when the cavities finish deep in the dentine or when the cavities lie close to the pulp. In a deep or extensive cavity, usually lining material was placed first. Lining may serve one or more of the following purposes; • • •

Protective lining/Pulp protection Therapeutic lining Structural lining a

b Fig-1.1 (a) and (b) Protective or Therapeutic

lining

Fig-1.2 Structural lining Protective lining/Pulp protection To protect dentine and pulp in metallic and in non-metallic restoration. The lining materials are; 1. Zinc Oxide and Eugenol Cement 2. Fortified Zinc Oxide Cement 3. Calcium Hydroxide Cement 4. Zinc Phosphate Cement Therapeutic lining To apply medicament such as chlorobutanol, carbolized resin, silver nitrate, and etc. The medicament may be applied directly to the dentine and covered with zinc oxide eugenol. Recommended materials are Fuji lining LC. Ledermix cement, Dycal (CaOH), Zinc oxide eugenol cement. Can be placed the thickness 0.5 mm or less. Structural lining The structural function of a lining is usually combined with its protective function. Recommended materials are Zinc oxide eugenol cement, kalzinol cement, Fiji IX, Fuji II, and Fiji II LC. Can be placed the thickness 2mm or more.

1.5 Cavity classification, location, and description: 1.5.1 Cavity classification.

G.V Black developed five standard cavity classifications and sixth class was added later. Class I: :Class I caries are developmental cavities in the pit and fissure of teeth (following Fig-1.3) They are located in: : The occlusal surface of the posterior teeth (premolar and molar) The buccal or lingual pit of molar The lingual pit near the cingulum of the maxillary incisors.

Class I cavity: The Fig-1.3 Shown the class I caries, (A).Occlusal surface of premolar and molar, (B).Buccal surface of Molar, (C ).Lingual surface of Maxillary incisors. Restoration with amalgam is recommended and some extents are counteracted by adhesive materials as composite and glass ionomers cement.

(c) Fig 1.3 Class I cavity Class II cavity: Class II caries are on the proximal (mesial or distal ) surface of the posterior teeth (premolars and molars) The following Fig-1.4(1) shown on the proximal surfaces of (A) premolar and molar, (B) placed prior to an MO or MOD restoration on the surface of premolar and molar The bottom part of the following figure is Class III cavity. 1 2 Fig-1.4 (1) Class II and (2) Class III caries. Class III cavity: Class III caries are on the interproximal surface (mesial or distal) of the anterior teeth (canines, lateral incisors and central incisors. The above Figure Fig-1.4(2) shown the class III cavity (M and D on the interproximal surface of central incisor and lateral incisor Fig-1.4 (2). Class IV Cavity: Class IV caries are on the interproximal surface (mesial or distal) of anterior teeth include the incisal edge. The Fig-1.5 showing class IV cavity.

Fig-1.5 Class IV cavity Class V cavity: Class V: Caries affecting on the cervical surfaces. The Fig 1.6 showing the class V cavity.

Fig-1.6A The class V cavity. Class VI cavity: Class VI: Cavity affecting by abrasion on facial surface of the teeth. The Fig-1.6 B shown the class VI cavity.

Fig-1. 6B Class VI cavity. Root service caries. As gingival recession The fig-1.7 shown root service cavity.

Fig-1.7 Root service cavity. 1.5.2 Location and description. Class I: Decay is diagnosed in the pits and fissures (Fig-1.8) of the occlusal surfaces of molars and premolars, buccal or lingual pits of molars, and lingual pits of maxillary incisors. Because most of this type of decay is confined to a small area, the dentist will choose to restore these surfaces with composite (tooth-colored) resins.

Fig-1.8 Decay in the pit and fissure of occlucal surface of molar and premolar. Class II: Decay is diagnosed in the proximal (mesial or distal) (Fig-1.9) surfaces of premolars and molars. Because this surface area is harder to detect visually, a radiograph is used to detect the decay. The design of the restoration will most commonly include the occlusal surface and may possibly involve more than two surfaces. The type of dental materials used to restore this classification is either silver amalgam (chosen for its strength) or newer composite (tooth-colored) resins designed for posterior teeth (chosen for esthetic appeal). If the tooth has extensive decay, the dentist may choose to crown the tooth with a gold or porcelain inlay, only, or crown.

Fig-1.9 Decay in mesial or distal surface of premolars and molars. Class III: Decay is diagnosed in the proximal (mesial or distal) (Fig-1.10) surfaces of incisors and canines. This decay is similar to that of class II, except it involves anterior teeth. It is easier for the dentist to access these surfaces with less tooth structure affected. The type of dental material used to restore this classification is composite (tooth-colored) resins (for esthetic appearance).

Fig-1.10 Decay in the proximal (mesial or distal) surfaces of incisors and canines. Class IV: Decay is diagnosed in the proximal (mesial or distal) (Fig-1.11) surfaces of incisors and canines. The difference between class IV and class III decay is that class IV involves the incisal edge or angle of the tooth. The type of dental material used to restore this classification is composite (toothcolored) resins (for esthetic appearance). If the tooth has extensive decay, the dentist may choose to crown the tooth with a porcelain crown.

tooth.

Fig-1.11 Decay in mesial or distal and incisal edge or angle of the

Class V: Decay is diagnosed in the gingival third of facial or lingual (Fig-1.12) surfaces of any tooth. This is also referred to as a smooth surface decay. The type of dental material used to restore this classification depends on which teeth are affected. If the decay occurs in posterior teeth, the dentist may choose silver amalgam; if anterior teeth are involved, composite (tooth-colored) resin will most likely be used.

Fig-1.12 Decay in the gingival third of facial or lingual surfaces.

Class VI: Decay is diagnosed on the incisal edge of anterior teeth and the cusp tips of posterior teeth (Fig-1.13). Class VI decay is caused by abrasion (wear) and defects. The dental material is chosen based on which teeth are involved. Fig-1.13 Decay on the incisal edge of anterior teeth and the cusp tips of the posterior teeth. 1.6 Procedures of cavity preparation: 1.6.1 Cavity preparation walls. Surfaces of the wall were prepared by operator internal boundaries of the cavity.

The surrounding walls of the cavity take the name of the surface of the tooth towards which they are placed; • Internal wall: An internal wall is a prepared cavity surface, which does not extend to external tooth surface. • Axial wall: An internal wall is parallel with the long axis of the tooth and adjacent or nearest pulp chamber or pulp canals. • Pulpal wall: An internal wall is both perpendicular to the long axis of the tooth and coronal to the pulp. • External wall: An external wall is a prepared cavity surface, which extends to the external surface of the tooth. • Mesial wall: An external wall towards the mesial surface of the cavity. • Distal wall: An external wall towards the distal surface of the cavity. • Occlusal wall: An external wall towards the occlusal surface of the cavity. 1.6.2 Cavity preparation floor. Floors (or seat) – term used which refers to the bottom or wall representing the deepest penetration in a cavity preparation (Fig-1.14). They are reasonably flat and perpendicular to the occlusal forces that are directed occluso-gingivally. Examples are: • The pulpal wall, which can also be known as pulpal floor. • The gingival wall, which also known as gingival floor (as in Class II or Class V). • Such floors provide a stabilizing seat for the restoration, thus distributing the stresses evenly in the tooth.

Fig-1.14 Cavity preparation floor. 1.6.3 Cavity preparation angles. Line angle term given to a line formed by the junction of two walls or a wall and a floor (Fig-1.15), named by combining the names of the two walls, e.g. • Mesio-buccal line angle: Disto-buccal line angle, Axio-pulpal line angle. • Internal line angle: A line angle which apex point, into the tooth (faciopulpal). • External angle: A line angle which apex point, away from the tooth (e.g., axio-pulpal)

Fig-1.15 Cavity preparation line angle (occlusal view) 1.6.4 Cavity preparation point angles. Point angle: Term given to a point where the three surfaces or three line angles (Fig-1.16) are meeting. It was named by combining the names of the three walls, e.g. • Mesio-biccal-pulpal point angle, Disto-lingual-pulpal line angle. Cavosurface angle: Term given to the angle of tooth structure formed by the junction of a prepared cavity wall and the external surface of the tooth. • Whilst the principles have been systematically set out in a specific number of steps and stages. There is a certain degree of overlapping, and principles

affecting stage frequently have a bearing on another. Additionally, some steps may be overlooked depending upon the clinical situation. Pulp protection is needed in the case where cavity preparation finishes deep into the dentin or lie close to the pulp. • We should aim to provide the best form, which will protect the tooth while achieving maximum durability of the restoration.

Fig-1.16 Cavity preparation point angle

Fig-1.17 Cavity preparation line angles, point angles and carvo-surface margin ( upper mesial view, lower occlusal view)Caries) must be removed.

2. MOISTURE CONTROL AND ISOLATION During the dental procedure, one of the most responsibilities is to maintain the clinical field. The tooth, surrounding tissue, and the oral cavity can be come a “catch all” for water, saliva, blood and tooth fragments. The type of procedure you are assisting in and the access to the area will be dictate the type of isolation method chosen. 2.1

Mouth Rinsing:

The two basic types of rinsing procedures used in dentistry are limited-area rinsing and complete mouth rinsing. Limited-area rinsing is performed frequently because the debris can be accumulated during the preparation o tooth. This must be quickly without delay in the procedure. The completed mouth rinse is performed at the completion of dental procedure. 2.1. 1 Performing a Mouth Rinse

Fig-2.1 Performing a mouth rinse.

1. 2. 3.

Equipment and supplies HVE tip Saliva ejector Air-water syringe

Procedure steps 1. Decide which oral evacuation system would be best for the rinsing procedure. 2. Grasp the air-water syringe in your left hand and the HVE or saliva ejector in your right hand. Limited-Mouth Rinse 1. Turn on the suction, and position the tip toward the site for a limited-area rinse. 2. Spray the combination of air and water onto the site to be rinsed. Purpose:

The combination of the air and water provides more force to clean the area thoroughly. 3. Suction all fluid and debris from the area, being sure to remove all fluids. 4. Dry the area by pressing the air button only. Full-Mouth Rinse 1. Have the patient turn toward you. Purpose: Turning the head allows the water to pool on one side, making it easier for you to suction. 2. Turn on the HVE or saliva ejector, and position it in the vestibule of the patient’s left side. Note: Position the tip carefully so that it does not come into contact with soft tissue. 3. With HEV or saliva ejector tip positioned, direct the air-water syringe from the patient’ maxillary right across to the left side, spraying all surfaces. 4. Continue down to the mandibular arch, following the same sequence from right to left. Purpose: This pattern of rinsing forces the debris to the posterior mouth, where the suction tip is positioned for easier removal of fluids and debris. 2.2 Oral Evacuation Method: 2.2.1 Saliva Ejector This instrument used to remove small amount of saliva or water from a patient’s mouth. It is small straw like tube has flexible to conform to many areas in the mouth (Fig-2.2). Fig-2.2 Saliva ejector. 2.2.2 High-Volume Oral Evacuation The high-volume oral evacuator (HVE) is stronger source of moisture control, commonly used during dental procedure. Maintain the mouth free from saliva, blood, water, and debris. Retract the tongue or cheek away from the procedure site. Reduce the bacterial aerosol caused by the high-speed handpiece. Oral Evacuation Caution: Improper or careless use of the HVE could cause soft tissue to be accidentally ‘sucked’ into the tip, and tissue damage could result. Keeping the tip at an angle to the soft tissue helps prevent this from happening. If the soft tissue is accidentally ‘sucked’ into the tip, rotate the angle of the tip to break the suction or quickly turn the vacuum control off to release the tissue. HVE Tips: The most commonly used HVE tips are made of a semihard plastic that is sterilized after a single use. Tips are also available in stainless steel, which also must be sterilized before reuse (Fig-2.3).

Fig-2.3 HVE tips. HVE tips are available with either straight or with a slight angle in the middle. All types have two beveled working ends (beveled meaning slanted.) The bevel is slanted downward for use in the anterior portion of the mouth. For use in the posterior portion of the mouth, the bevel is slanted upward. When placing the HVE tip into the handle of the suction unit, the tip is pushed into place through a plastic protective barrier, which will cover the HVE handle. If the incorrect end of the tip has been placed in the suction, do not turn it around; it is now contaminated and must be replaced with a new tip.

Holding the Oral Evacuator: The oral evacuator may be held in two ways: either the thumb-to-nose grasp or pen grasp (Fig-2.4). Either method provides control of the tip, which is necessary for patient comfort and safety. Many assistants alternate between positions, depending on the resistance of the tissue to retract and the area being treated.

Fig-2.4 Method of holding the oral evacuator tip: Top; thumb-to-nose grasp, and Bottom; pen grasp. When assisting a right-handed dentist, hold the evacuator in the right hand. When assisting a left-handed dentist, hold the evacuator in the left hand. The other hand is then free to use the air-water syringe or transfer instruments to the dentist as needed. To be most efficient in HVE placement, you should position the HVE tip in the mouth first, and then the dentist can position the hand piece and mouth mirror (Fig-2.5).

Fig-2.5 A The HVE tip is placed on the lingual surface and slightly distal to the tooth being prepared. On

the

mandibular it is also used to retract the tongue (Placement of HEV tip on maxillary and mandibular right side). Fig-2.5 B The HVE tip is placed on the opposite surface of

the

tooth being prepared; for example, if the dentist is working

on surface.

the facial surface, the HVE tip is positioned on the lingual (Placement of HEV tip on maxillary and mandibular anterior side).

Fig-2.5 C The HVE tip is placed on the buccal surface and slightly distal to the tooth

being cheek. side).

prepared, also helping to retract the (Placement of HEV tip on maxillary and mandibular left

2.2.3 Positioning the High-Volume Evacuator During a procedure 1. 2. 3.

Equipment and Supplies Sterile HVE tip Plastic barrier cover for HVE handle and hose Cotton rolls.

Procedure Steps. 1. Place the HVE tip in the holder by pushing the end of the tip into the holder through the plastic barrier. Purpose: Leaves the opposite end exposed and ready for use. 2. If necessary, use the HEV tip or a mouth mirror to gently retract the cheek or tongue. 3. For a mandibular site, place a cotton roll under suction tip. Purpose: Provides patient comfort, aid in stabilizing tip placement, and prevent injury to the tissue. 4. Place the bevel of the HEV tip as close as possible to the tooth being prepared. Purpose: Suction will draw the water into the tip immediately after it leave the tooth being prepared. 5. Position the bevel of the HEV tip parallel to the buccal or lingual surface of the tooth being prepared. 6. Place the upper edge of the HEV tip so that it extends slightly beyond the occlusal surface. Purpose: Suction will catch the water spray from the hand piece as it leaves the tooth being prepared.

Fig-2.6 Posterior Placement. Placement.

2.3

Fig-2.7 Anterior

Isolation techniques:

2.3.1 Cotton Rolls During tooth preparation, water is expressed from the high speed hand piece to cool the tooth and remove debris. However, when placing a composite or amalgam restoration or when cementing a cast restoration a clean, dry environment is necessary. One method of ensuring dry conditions is the use of cotton rolls. When a dental dam is not an option, cotton roll isolation is used as an alternative method to control moisture in the operative area. (Isolation, as used here, means to keep the area separated and dry.) Cotton rolls are available in a variety of sizes and are flexible so they can be bent to fit an available space. Some cotton rolls have a light coating on the surface to make them slightly stiff. A softer type of cotton roll is not coated, but is wrapped with a cotton thread. There are advantages and disadvantages to using cotton rolls:

1. 2. 3.

Advantages Can be placed quickly and securely Are simple to use No additional equipment is needed for placement.

Disadvantages 1. Do not prevent contamination of the area by the patient tongue. 2. Do not prevent debris from dropping into the mouth or throat. 3. If removed, dry cotton rolls may adhere to the oral mucosa, which can injury the tissue. 4. Must be replaced if they get wet before the procedure is completed. 2.3.2 Cotton Roll Placement

When part of the maxillary arch is isolated, cotton rolls are placed on the cheek side of the teeth in the mucobuccal fold. This fold holds the cotton rolls securely in place. (The mucobuccal fold is the area where the masticatory mucosa covering the alveolar ridge turns upward and becomes the lining mucosa of the cheek) (Fig-2.8) A

B Fig-2.8 A and B , Cotton roll placement for the maxillary

arch.

Because of movements of the tongue and the tendency of saliva to pool in the floor of the mouth, cotton roll isolation is more difficult to achieve in the mandibular arch. Cotton rolls are placed in both the mucobuccal fold and on the lingual side of the arch (Fig-2.9). A

B

Fig-2.9 A and B, Cotton roll placement for mandibular arch.

When the anterior portion of the mandible is isolated, cotton rolls and a saliva ejector can be used. To isolate the posterior portion, two cotton rolls and a saliva ejector may be used (Fig-2.10). Depending on the location, cotton rolls are placed and removed with either cotton pliers or gloved fingers. If the cotton rolls become saturated. Fig-2.10 cotton roll placement for anterior.

2.3.3 Related Aids Dry Angle: Some dentist will use a triangle-shaped absorbent pad to help isolate posterior areas in both the maxillary and mandibular arches. The pad is placed on the buccal mucosa over Stensen’s duct (Fig-2.11). (This duct from the parotid gland is located opposite the maxillary second molar.) These pads block the flow of saliva and protect the tissue in this area. Follow the manufacturer’s directions for placement and if necessary replace pad if they become soaked before the procedure is completed. To remove, use water from the air-water syringe to thoroughly wet the pad before separating it from the tissue.

Fig-2.11 Application of a dry angle. 2.3.4 Placement and removal of Cotton Rolls 1. 2. 3.

Equipment and Supplies Basic setup Cotton rolls Air-water syringe Maxillary placement

1. Have the patient turn toward you with their chin raised. Purpose: Provide better visualization and easier placement of cotton roll. 2. Using the cotton pliers, pick up a cotton roll so that it is positioned evenly with the beaks of the pliers. 3. Transfer the cotton roll to the mouth, and position it securely in the mucobuccal fold closet to the working field. Note: Once you place the cotton roll with the pliers, you may want to use your gloved finger or handle end of the cotton pliers to push the cotton roll further into the mucobuccal fold. 4. This placement can be used for any location on the maxillary arch. Cotton rolls placement for maxillary. Mandibular placement 1. Have the patient turn toward you with the chin lowered. Purpose: Provides better visualization and ease in the placement of the cotton roll. 2. Using the cotton pliers, pick up a cotton roll so that it is positioned even with the beaks of the pliers. 3. Transfer the cotton roll to the mouth, and position it securely in the mucobuccal fold closet to the working field. 4. Carry the second cotton roll to the mouth, and position it in the floor of the mouth between the working field and the tongue. Note: Have the patient lift the tongue during the placement and then relax to help secure the cotton roll in position. 5. If you are placing cotton rolls for the mandibular anterior region, bend the cotton roll before placement for better fit. 6. If using saliva ejector for the procedure, place it after the cotton roll is in position in the lingual vestibule. Cotton rolls placement for mandibular. Cotton roll removal 1. At the completion of a procedure, remove the cotton roll before the full mouth rinse. If the cotton roll is dry, moisture it with water from air-water syringe. Purpose: Dry cotton rolls will adhere to the oral mucosa lining and tissue may damage when a dry cotton roll is pulled away from the area. 2. Using cotton pliers, retrieve the contaminated cotton roll from the site. 3. If appropriate for the procedure, perform a limited rinse. 2.4

Rubber dam isolation:

The dental dam is a thin latex barrier used to isolate a specific tooth or several teeth during treatment (Fig-2.12). These teeth are referred to as being isolated. The dental dam is applied after the local anesthetic has been administrated and while the dentist is waiting for it take effect. Before the application of the dental dam, the isolated teeth should be clean and free of plaque or debris. If not removed, the plaque or debris could be dislodged and injure the gingival tissue. When indicated, tooth brushing or selective coronal polishing is performed before dam placement. Before placing the dental dam, review the patient’s medical history for any indications of latex sensitivity. If this is a problem, the dentist must be consulted before the application is continued. Fig-2.12 Dental dam.

2.4.1 Dental Dam Equipment The specialized equipment used for rapid and efficient placement of dental dam is shown in Figure-2.13 and described in table 2.1. Indications for use of dental dam a. It serves as an important infection control protective barrier. b. It safeguards the patient’s mouth against contact with debris, acid-etch materials and other materials during treatment. c. It protects the tooth from accidentally inhaling or swallowing debris, such as small fragments of a tooth or scraps of restorative material. d. It protects the tooth from the contamination of saliva or debris if pulpal exposure accidentally occurs. e. It protects the remainder of oral cavity from exposure to infectious material when an infected tooth is opened during endodontic treatment. f. It provides the moisture control that is essential for the placement of restorative materials. g. It improves access during treatment by retracting the lips, tongue, and gingival. h. It provides better visibility because of the contrast of color of the dam and the tooth. i. It increases dental team efficiency, discourages patient conversation, and may reduce time required for some treatment.

Fig-2.13 Dental dam setup for application. Table-2.1 Dental dam and equipment.

Dam Material

Type of Equipment Description of Equipment

Material comes in latex or latex-free material. Size is 6 x 6 0r 5 x 5. Comes in a wide range of colors. There are three gauges of thickness (thin, medium, and heavy). Dental dam frame

It is a “U” shaped frame made of either plastic or metal stretches the material away from the face and being worked on. Dental dam napkin

A cotton absorbent sheet placed between the dental dam and patient. Lubricant A water-soluble material that can be placed on the underside of the dam around the punched area for easier placement between tight contacts. Dental dam punch

A hole punch device used to create the holes in the dam that expose the teeth to be isolated. The sizes used for specific teeth are: No.1 Mandibular incisors No.2 Maxillary incisors No.3 Premolars and canines No.4 Molars and bridge abutments No.5 Anchor tooth with the clamp Dental dam stamp

Stamp designed in the shape of dental arch that imprints teeth on the dental dam to be punched. Dental dam forceps

A forceps that is used in the placement and removal of the dental dam clamp. Dental dam clamps

A crown-shape piece of metal that anchors the dental dam material on a tooth. There are many designs of clamps that fit the contour of each tooth in the mouth. For safety purposes, it is important to always ligate to bow portion of a clamp with floss before placing in the mouth. This will prevent the clamp from being accidentally swallowed.

2.4.2 Preparation of the Dental Dam Application Each application of dam is preplanned to accommodate the dentist’s preferences, the tooth and teeth involved, and the procedure to be preformed. Several important factors must be included in planning for holes to be punched in the dental dam. i. The arch, its shape, and any irregularities, such as missing teeth or a fixed prosthesis ii. The number of teeth to be isolated iii. Identification of the anchor tooth and location of the key punch hole iv. The size and spacing of the other holes to be punched; (the anchor tooth holds the dental dam clamp, and the keypunch hole covers the anchor tooth). Maxillary Arch Applications In preparation for maxillary application, the dam material is stamped or marked. This mark automatically designates the margin of dam for these holes. If the patient has a mustache or very thick upper lip, it is necessary to allow extra space for the anterior teeth area.

Mandibular Arch Applications. In preparation for mandibular application, the dam is stamped or marked. Because of the small size of the mandibular anterior teeth, the holes are punched closer together than those for posterior teeth. Curve of the Arch It is necessary to make the adjustments to accommodate an extremely narrow or wide arch. Failure to do this will increase the difficulty when inverting the edges of the punched holes of the dam. Bunching the stretching on the lingual aspect of the dental dam occur if the curve of the arch is punched too narrow or too wide. Folds and stretching of the dam on the facial aspect occur if the arch is punched too curved or too narrow. Malaligned Teeth If a tooth or teeth are misaligned within the dental arch, special consideration of their position is taken before the dental dam is punched. (Malaligned and malposed mean that the individual tooth is not in its normal position within the dental arch.) If a tooth is lingually positioned, the hole punch size remains the same, but the hole is placed about 1 mm lingually from the normal arch alignment. If the tooth is facially positioned, the hole punch size remains the same, but the hole is placed about 1 mm facially from the normal arch alignment. Teeth to be Isolated Single-tooth isolation is used commonly for endodontic treatment and for selective restorative procedures, such as Class V restorations. Some dentists choose to isolate only the tooth to be treated. Others prefer to have two teeth isolated so that the second tooth acts as an anchor tooth to hold the clamp. During treatment in the posterior area, this provides more stability and better visibility. For multiple-tooth isolation, in which optimum stability is needed, it is desirable to have the quadrant isolated having this many teeth isolated counteracts the pull on the dam that is created by the curvature of the teeth in the arch. When anterior maxillary teeth are to be treated, maximum stability is achieved by isolating the six anterior teeth (canine to canine). Key Punch Hole The anchor tooth holds the dental dam clamp. The key punch hole is punched in the dental dam to cover the anchor tooth. A larger, number 5-size hole is necessary for the key punch because it must also accommodate the clamp. Hole Size and Spacing The size of each hole selected on the dental dam punch must be appropriate for the tooth to be isolated. A correctly sized hole allows the dam to slip easily over the tooth and fit sungly in the cervical area. This is important to prevent leakage around the dam. In general, the holes are spaced from 3.0 to 3.5 mm between the edges, not the centers, of the holes. This allows adequate spacing between the holes to create a septum that slips between the teeth without tearing or injuring the gingival. The septum is the portion of the dental dam between the holes of the punched dam. During application, this portion of the dam is passed between the contacts (Septum is singular, septa is plural). Ethical Implications In the application of the dental dam, you may be asked to place this by yourself. If this is the cave, verify that this is a legal function in your state for dental assistants and that you have had special training in the application process. 2.4.3 Preparation, Placement, and Removal of Dental Dam. Equipment and supplies 1. Basic setup 2. Precut 6-by-6-inch dental dam 3. Dental dam stamp and inkpad or template and pen 4. Dental dam punch

5. Dental dam clamp or clamps with ligature attached 6. Dental dam clamp forceps 7. Young frame 8. Dental dam napkin 9. Dental tape or waxed floss 10. Cotton rolls 11. Lubricant for patient’s lips 12. Lubricant for dam 13. Black spoon 14. Crown and bridge scissors Fig-2.13 The basic setup for dental application. Patient preparation 1. Check the patient’s record for contraindications and to identify the area to be isolated. Inform the patient of the need to place a dental dam, and explain the steps involved. 2. Assist the dentist in the administration of local anesthetic. The operator will determine which teeth are to be isolated and note whether there are any malposed teeth to be accommodated. 3. Apply lubricating ointment to the patient’s lip with a cotton roll or cotton tip applicator. Note: The patient’s comfort is of concern throughout the placement and removal of the dental dam. 4. Use the mouth mirror and explorer to examine the site where the dam is to be placed. It should be free of plaque and debris. Purpose: If the dam is placed in an area with plaque and debris, the dam could push the plaque and debris into the sulcus and irritate the gingival tissue. Note: If debris or plaque is present, selective tooth brushing or coronal polishing is performed on these teeth before the application of the dental dam. 5.Floss all contacts involved in the placement of the dental dam. Purpose: Any tight contacts may tear the dam. Punching the dental dam 1. Use a template or stamp to mark on the dam the teeth to be isolated. 2. Correctly punch the marked dam according to the teeth to be isolated. Be sure to use the correct size of punch hole for the specific tooth. 3. If the teeth have tight contacts, lightly lubricated the holes on the tooth surface (under surface) of the dam. Purpose: This eases placement of dental dam over the contact area of the teeth. Placing the clamp and frame 1. Select the correct size of clamp. 2. Secure the clamp by tying a ligature of dental tap on the bow of the clamp. 3. Place the beaks of the rubber dam forceps into the hole of the clamp. Grasp the handles of the rubber dam forceps, and squeeze to open the clamp. Turn upward, and allow the locking bar to side down to keep the forceps open for placement. 4. Place yourself in the operator’s position, and adjust your patient for easier

access. 5. Retrieve the rubber dam forceps. Positions the lingual jaw of the clamp first, then the facial jaw during placement, keep an index finger on the clamp to prevent the clamp from coming off before it has been stabilized on the tooth. 6. Check the clamp for fit.

Fig-2.15 Lingual placement. finger on clamp

Fig-2.17 Position the frame over the dam. dam.

Fig-2 16 Keep an index

Fig-2.18 Use the floss and pushing the

7 Transfer the dental dam to the side; stretch the punched hole for the anchor tooth over the clamp. 8 Using cotton pliers, retrieve the ligature and pull it through so that it is exposed and easy to grasp if necessary. 9 Position the frame over the dam and slightly pull the dam, allowing it to hook onto the projections of the frame. Purpose: Ensures a smooth and stable fit. 10 Fit the last of the dam over the last tooth to be exposed at the opposite end of the anchor tooth. Purpose: This stabilizes the dam and aids in locating the remaining punch holes for the teeth to be isolated. 11 Using the index fingers of both hands, stretch the dam on the lingual and facial surfaces of the teeth so that the dam slides through each contact area. 12 With a piece of dental tape or waxed floss, floss through the contacts, pushing the dam below the proximal contacts of each tooth to be isolated. Note: Slide the floss through the contact rather than pulling it back through the contact. This will keep the dam in place. 13 If the contacts are extremely tight, use floss or a wedge placed into the interproximal area to separate the teeth slightly. 14 A ligature is placed to stabilize the dam at the opposite end of the anchor tooth.

4. Inverting the dental dam 1. Invert, or reverse, the dam by gently stretching it near the cervix of the tooth. a. Purpose: Inverting the dam creates a seal to prevent the leakage of saliva. 2. Apply air from the air-water syringe to the tooth being inverted to help in turning the dam material under. a. Purpose: When the tooth surface is dry, the margin of the stretched dam usually inverts into the gingival sulcus as the dam is released. 3. A black spoon or burnisher can be used to invert the edges of the dam. 4. When all punched holes are properly inverted, the dental dam application is complete. 5. If necessary for patient comfort, a saliva ejector may be placed under the dam. This is positioned on the floor of the patient’s mouth on the side opposite the area being treated. 6. If the patient is uncomfortable and has trouble breathing only through the

nose, cut a small hole in the palatal area of the dam by pinching a piece of dam with cotton pliers and cutting a small hole near the palatal area. Fig-2.19 Inverting the dam. 5. Removing the dental dam 1. If a ligature was used to stabilize the dam, remove it first. If a saliva ejector was used, remove it. 2. Slide your finger under the dam parallel to the arch and pull outward so that you are stretching the holes away from the isolated teeth. Working from posterior to anterior, use the crown and bridge scissors to cut from hole, creating one long cut. 3. When all septa are cut, the dam is pulled lingually to free the rubber from the interproximal space. 4. Using the dental dam forceps, position the beaks into the holes of the clamp, and open the clamp squeezing the handle. Gently slide the clamp from the tooth. 5. Remove both the dam and the frame at one time. 6. Use a tissue or the napkin to wide the patient’s mouth lips, and chin free of moisture. 7. Inspect the dam to ensure that the entire pattern of the torn septa of the dental dam has been removed. 8. If a fragment of the dental is missing, use dental floss to check the corresponding interproximal area of the oral cavity. Purpose: Fragment of the dental dam left under the free gingival can cause gingival irritation.

Fig-2.20 Removing the clamp.

Fig-2.21 Remove the clamp gently.

Fig-2.22 Remove the dam and frame at one time

3. CARIES EXCAVATION AND TEMPORARY RESTORATION. 3.1 Access cavity and caries excavation. 3.1.1 The establishment access cavity and outline form. • In based primarily on the location and extent of the carious lesions, tooth fracture, or erosion. • In carious lesion, the rough outline form is established after penetration into carious dentine and removal of enamel overlying the carious dentine. The final outline is not established until carious dentine and its overlying enamel have been removed. • The initial cutting can be achieved by using either flat fissure tungsten carbide or a small round diamond bur.

• The above caries should be removed either by using slow speed stainless steel round bur or spoon excavators (hand instruments). • Caries at dentinoenamel junction (DEJ) and soft, infected dentine (active caries) must be removed. • With the used of plastic (frasaco) teeth in the laboratory, access is gained by preparing an initial depth of 0.2 to 0.8 mm below the dentinoenamel junction. • Cavity margins are placed in the positions where they will occupy the final preparation.

Fig-3.1 Access cavity and outline form.

Fig-3.2 Depth of cavity preparation and pulpal relation. 3.1.2 The establishment of resistance form. Defined as the design of the internal form of the cavity preparation or walls that will enable both the restoration and the tooth, to withstand the masticatory forces without fracture. The fundamental principles involved in obtaining resistance form are as follow: • Enamel walls are supported by sound dentine. • Utilize the proximal box shape with a relatively flat floor. • Junction of the proximal box walls should be rounded off to avoid sharp line angle. • Proximal axial wall is at the right angles to the pulpal and gingival floor. • Rounded and internal line angle to reduce stress concentration. • Cavo-surface line angles are kept away from areas of stress such as inclination and tips of cusps. • The axiopulpal line angle should be rounded off to allow reasonable thickness of material in this area. • Provide enough thickness of restorative material to resist fracture under load (1.5 mm to 2.0 mm occlusogingivally). • Restrict the extension of external wall to allow strong cusp and ridge to remain with dentine support. • Cusp capping weak cusps in extensive cavity preparations.

3.1.3. The establishment of retention form. Defined as that shape of the prepared cavity that resists displacement or removal of the restoration from tipping or lifting forces. Since retention needs are related to the restorative material used, the principles of retention form varies depending on the used restorative materials. • For amalgam restoration , in class I and class II cavity preparations, the materials is retained in the tooth by developing external cavity wall which converge occlusally. • For composite resin restoration, in class III and class IV cavity preparation, the external walls diverge outwardly to provide strong enamel margins. • In some cases, retentive coves, grooves, locks or dovetails are incorporated to increase the retention of these restorative materials to the tooth structure. • Composite restorations are retained in the tooth by a physical bond, which

develops between the material and acid-etched tooth structure. • Glass Ionomer Cement (GIC) restorations are retained in the tooth by chemical bond which develops between the material and conditioned tooth structure. 3.1.4. Convenience form. Defined as the shape or form of the cavity which allows adequate observation, accessibility and ease of operation during preparation and restoration of the tooth. • Widening access to permit space for bur and instruments (instruments for tooth cutting, instruments for carrying restorative materials and instruments for placing and condensing the restorative materials) upon placement of restorative material. • Convenience form which involves the removal of sound, strong tooth structure should be limited and which is necessary.

3.1.5 The treatment of residual caries. Removal of remaining carious dentine, applies primarily to the caries in the deepest part (pulpally) of the preparation. Other caries have been removed when the outline form was established. It may also include (where applicable), the elimination of any defective restoration left in the tooth after initial cavity preparation and to consider as follow: • Remaining deep caries is carefully removed with a slow speed stainless steel round bur (if possible, under water spray) or a sharp excavator. • Pay particular attention to the lateral spread of caries at the DEJ; ensure to clean DEJ first before attempting deeper caries.

3.1.6 Finishing of enamel walls and cavo-surface margins. This is ensure the cavo-surface margin are smooth and continuous to facilitate finishing of restoration margins. The objectives of finishing the cavosurface margins and walls are: • To provide a mechanically strong interface between tooth and restoration. • To obtain the best possible marginal seal at the tooth / restoration interface. • To obtain an optimal angle of the materials at the tooth / restoration interface. • To allow for a smooth marginal junction. • To define where the restorative materials should end. Should remove any sharp edges or margin, which could be a stress concentration area or point and might break or fracture. Factors to be considered are: • Enamel walls must follow the direction of the enamel rod. • For restoration not utilizing bonding (e.g.: using amalgam), any unsupported weak or fragile enamel must be removed. • For bonded restorations (e.g. using composite resin, GIC, compomer or resinmodified GIC), enamel that is not supported by dentin and is not exposed to significant occlusal loading is frequently allowed to remain in place and is

reinforced by bonding to its internal surface. 3.1.7 The toilet of the cavity or cleaning of cavity. Final procedures in cavity preparation included as follow: • Washing all debris from the cavity (tooth chips, saliva, blood etc) using air-water spray. • Ensure that the cavity is not wet, lightly dry the cavity using air spray (be careful not to dessicate exposed dentin). • Inspect cavity carefully for any traces of remaining debris, caries, fragile enamel, and deminearlized tooth structure. • Advice to the patient: In the clinic, every patient should be explained about the treatment given and must given an advice post-operatively. For example is to advise patient not to eat hard food at new amalgam restoration site due to a risk of break because amalgam is not fully set within 24 hours. Others include the oral hygiene care.

3.2

Temporary restoration.

3.2.1 Introduction. Operative dentistry among others involves restoration of carious teeth. In this module will learn the technique of removing caries while maintaining the health and integrity of the pulp. The objectives of this simulation study are: • Detect carious lesions on extracted teeth. • Use the correct instruments to gain access and remove carious dentine at the DEJ (periphery of cavity) as well as over the pulp. • Identify carious dentine, which needs to be removed (infected dentine) and those, which can be left behind (affected dentine). • List the temporary restorative materials, which is available in the dental faculty. • Correctly mix and apply the temporary restorative material into the cavity. 3.2.2 Note on principles of caries excavation. • Remove caries at the peripheral first before doing the central part. Remaining dentine at the periphery of the cavity must be clear of stains and hard dentine. All decayed, stained and softened dentine must be removed peripherally for a distance of about 1 to 1.5 mm from the amelo-dentinal junction (ADJ) (Fig3.1). • Removal of central caries – this must be done carefully to avoid exposing the pulp iatrogenically. Although can leave hard and stained dentine in the central part of the cavity (overlying the pulp).

F ig-3.1 Caries excavation.

In any carious cavity, beneath the active caries there is a layer of possibly stained and definitely decalcified dentine. This is healthy and should not be removed. If remove all stained dentine, will be remove the healthy layer above the pulp and will expose the pulp. 3.2.3 Restoration with Zinc Oxide and Eugenol. Simple zinc oxide and eugenol, mixed to firm putty consistency, or the same cement containing an accelerator such as zinc acetate, are equally useful in this role. Zinc oxide and eugenol is frequently said to be obtunded, and the cement mixed with clove oil even more so. Certainly, it is non-irritant to freshly cut dentine, but it frequently leaves a cavity highly sensitive except when it has remained for some months. There are occasions when the deepest layer overlying the pulp can be left in a position when the remainder is removed. This deep layer may then be used as a lining or sublining to the permanent restoration.

There are 2 exercises should be complete; ESERCISES TASK TEETH Exercise 1 Caries excavation and temporary restoration using Zinc Oxide Eugenol ( Kalzinol). Natural teeth / Frasaco teeth: 1 molar (upper or lower), carious and cavitated notbinvoling the proximal surfaces. Exercise 2 Caries excavation and temporary restoration using Rein Modified Glass Ionomer cement (Fuji VII) Natural teeth / frasoco teeth: 1 molar (upper or lower), carious and cavitated not involving the proximal surfaces.

The equipment and materials needed are as listed below: No.

Stage Equipment / Material 1 Access TC High speed bur 010 / 012 2 Caries free Slow speed round bur (size 014 -023) 3 Lining Calcium hydroxide (Dycal) . Glass Ionomer Cement (Vitrebond) 4 Temporary Restoration (Cement) Zinc Oxide Eugenol (Kalzinol) Glass Ionomer Cement (Fuji VII) 5 Cement mixing Glass slab Spatula 6 Placement of restorative material Plastic Instrument 7 Others Gauze • Gain access the cavity by removing some overlying unsupported enamel with high-speed bur. • Remove all the caries along the DEJ using a large slow speed round bur. • Remove soft and leathery carious dentine from the pulpal floor using a spoon excavator. • Restore the cavity using Zinc Oxide Eugenol (Kalzinol). • Ensure that the restoration is homogenous with the tooth. Fig-3.2 Access cavity with Remove the caries High speed bur. Low speed round bur.

Fig-3.3

Fig-3.4 Placement of temporary restorative material into the class II prepared molar. 3.2.4 Restoration with GIC (Fuji VII). • Gain access, remove all caries from DEJ and soft and leathery dentine from the pulpal floor, after that wash and dry. • Apply dentine conditioner for 15 seconds, wash and dry. • Mix Fuji for 10 seconds. • Apply fuji into the cavity and shape the restoration. • Light cure the restoration for 15 seconds • Check the restoration; ensure that it conforms to the anatomy.

Fig-3.5 Apply conditioner.

Fig-3.6

Fuji VII

capsule.

Fig-3.7 Fuji capsule mixer. the cavity

Fig-3.8 Placed the Fuji into

Fig-3.9 Shape the restoration. 3.2.5 Restoration with Zinc Phosphate Cement. Zinc phosphate cement may also be used as a temporary filling. Small wisps of cotton wool lightly impregnated with clove oil or eugenol may be placed over the pulp and into the deeper undercuts to reduce the possibility of irritation. This cement may be used as a thick creamy mix or as a thick mix of putty consistency. If a thick creamy mix is used, a blunt-ended probe is the most suitable instrument for teasing the cement, a small portion at a time, into the appropriate part of the cavity. With cement of putty consistency, a discrete portion of cement is carried to position on a small round-ended plastic instrument is suitable. When in position, the cement should be tamped firmly against the cavity surface and conformed to the correct shape with plastic instruments moistened with alcohol.

Fig-3.10

Mixing zinc phosphate cement with stainless Steel spatula on thick glass slab.

3.2.6 Restoration with Gutta-percha. Temporary gutta-percha can be used for short periods in simple cavities affecting one surface, or in compound cavities well enclosed and not exposed to excessive bite. It is unreliable as a cavity seal, but if the surface of the mass

is made tacky by immersion in chloroform before insertion, it is probable that closer adaptation to cavity walls can be achieved. This particular is easy to remove but often leaves the dentine of the cavity hypersensitive, to reduce it by applying carbolated resin to the cavity before insertion of gutta-percha. Although the wide range of usefulness temporary cement material is zinc oxide and eugenol. 3.3

Mounting the teeth.

Some of the exercises that will involve using natural teeth which mounted on plaster blocks. In this exercise, how to mount the teeth in the blue Perspex tray. First mix the plaster with water thickly and pour into the Perspex tray, then the tooth mounted onto the plaster in the middle of tray. Please note this mounted teeth can use for the exercise (1) caries excavation and temporary restoration and (2) class V restoration. Mount the teeth list below. They are listed according to the order of exercise in this simulation clinic. If you do not have all the teeth now, you may mount them in stages, i.e. mount the teeth that you will be using first. You must mount at least six teeth for each exercise; the teeth which going to use, should be mounted in the middle. 3.3.1. The teeth need for mounting. NO. TEETH CRITERIA EXERCISE 1 2 Molars (upper/lower) Large occlusal caries, preferably not involving the proximal surfaces. Caries excavation and temporary restoration. Mount on plaster block for table to exercise.

2 2 Canines or premolars (upper/lower) Sound or with

abrasion cavity on the baccal surface.

Class V restoration. Mount on plaster block for table to exercise. Ensure that at least 5 mm of root surface is exposed.

3 2 Incisors (upper/lower)

Small or medium size caries on the proximal surface.

Class III restoration

COMPETENCY TEST Must be an upper incisor tooth

4 1 Incisors (upper/lower)

Sound or with proximal caries involving an incisal angle/edge.

Class IV restoration. 5 1 molar (upper/lower)

Sound or stained fissure.

Fissure sealant. 6 1 molar (upper/lower) Caries localized in a pit, other fissures sound.

Preventive Resin Restoration. 7 2 premolar and/or molar (upper/lower) Small caries on proximal surface (< 1/3 width of tooth). Class II composite resin restoration.

______________ COMPETENCY TEST 8 1 molar (upper/lower)

Caries (medium/large) on occlusal surface.

Class 1 amalgam restoration. 9 1 premolar or molar (upper/lower) Medium or large caries on the proximal surface (> 1/3 width of the tooth). Large Class II amalgam restoration. 10 1 molar (upper/lower)

Large caries involving 1 or more cups.

Pinned and bonded amalgam.

4. PREVENTIVE RESIN RESTORATION. 4.1

Fissure sealant

Sealant restoration was born, for the use of pit and fissure sealants. Dental sealant is highly effective in preventive dental caries in the pit and fissure areas of the teeth. 100% caries protection by properly placed and retained the dental sealants on the tooth surface. The technique restore the carious area and seals the rest of the fissures. The restoration is indicated where a cavity is present (either a microcavity in the enamel or in a cavity with dentine at its base). The lesion will usually be visible on a bite viewing radiograph as an area of radiolucency in the dentine. Fissure sealant is also can be placed on molar during development, to prevent decay.

Fig-4.1 Placed Fissure Sealant Application for dental sealants. The technique for applying fissure sealant on a molar tooth, which should not have carious. The equipments and materials are as Fig-4.1.

Fig-4.2 Materials and equipments for dental sealants. Applying fissure sealant on a molar tooth: • Apply rubber dam. • Clean the tooth using prophylaxis paste and brush, wash and dry. • Acid etch for 15 seconds, wash and dry. • Placed fissure sealant-just enough to flow within fissures and grooves. • Light cure for 10 seconds. • Check occlusion.

Fig-4.3 Place the etching on cleaned molar tooth.

Fig-4.4 Light curing for 10 sec.

Fig-4.5 Checking Occlusion

Fig-4.6 Completed of fissure sealant on permanent molar. 4.2

.1 Pit restorations with Composite resin.

Cavity preparation: o o o o o cure. o o

Isolated with rubber dam. A small round bur is used to remove caries and access cavity. If the cavity much larger, place the lining and then place etching. GIC place as second liner. The cavity is filled with an increment of posterior composite and light Place final increment of composite and light cure. Completed restoration.

Fig-4.7A Composite Resin materials set.

Fig-4.8 Occlusal cavity in molar.

is placed.

Fig-4.10 Lining is placed.

Fig-4.9 Access Cavity.

Fig-4.11

GIC

Fig-4.12 Placed Composite and Light-cure composite.

Fig-4.14 Completed restoration.

After 5 years.

Fig-4.16 After 9 years After 14

Fig-4.13 Place final

Fig-4.15

Fig-4.17

years.

4.2.2 Pit restoration GIC Light-Cure. Glass ionomer cement (Fig-4.17) is one of the newer cement systems. The GIC (ketac molar) is type one system of GIC light-cure, which also can be used for pit and fissure sealant (Fig-4.18 to Fig-4.23).

Fig-4.17A Various brand name of GIC.

Fig-4.19 B Ketac Molar GIC material including liquid, powder and conditioner.

Fig-4.18 conditioner.

Remove the caries and rinse.

Fig-4.20 Dry the cavity. Mixing the GIC

Fig-4.22 Place the GIC

Fig-4.19 Apply the

Fig-4.21

Fig-4.23 Complete restoration.

5. ACID-ETCH TECHNIQUE AND ABRATION 5.1

CAVITY

RESTORATION.

Acid-etch technique.

Equipment and supplies: Basic setup, cotton rolls /dental dam for isolation, applicator (cotton pellets for liquid etching and syringe tip for gel), etching material, high-velocity evacuator, air-water syringe and timer(Fig-5.1). Procedure: 4. The prepared tooth must be isolated with rubber dam or cotton rolls 5. The surface of the tooth must clean and free from any debris, plaque or calculus. 6. After clean, dry surface carefully. 7. The etching material is place only where it is needed (Fig-5.2). 8. The tooth structure is etched from 15 to 30 seconds. 9. After etching, the surface is thoroughly rinsed and dried for 15 to 30 seconds. 10. An etched surface has a frosty-white appearance.

Fig-5.1 Basic set for etching technique.

Fig-5. 2

5.2

Place the Etching gel on the molar tooth.

Abrasion cavity restoration.

Defects occurring at the cervical areas of the teeth may be due to the effects of caries, abrasion from toothbrush and tooth paste, erosion and a fraction. In this exercise, will simulate an abrasion cavity on a natural tooth and restore it using GIC. Restoration of abrasion cavity with Fuji II : • Prepare a cervical abrasion cavity on the buccal surface a canine or premolar tooth (using pear bur). This step will only be done if using a sound natural tooth. • Choose a suitable cervical matrix, bend it to shape. • Pumice the tooth surface, wash and dry. • Apply conditioner for 15 seconds, wash and dry. • Place the GIC (Fuji II) material into the cavity, cover with the cervical matrix, remove any excess material and wait until the material is set. • Remove the matrix. • Apply the bonding agent on the restoration and light cure. • Final restoration, polishing (only if necessary) should be done 24 hours after placement. Fig-5.3 Abrasion cavity 3mm height and width.

Fig-5.4 Band with matrix.

Fig-5.5 Pumice the tooth surface. conditioner.

Fig-5.7 Remove the matrix.

Fig-5.6 Applying the

Place the Fuji II.

Fig-5.8

Fig-5.9 Place the bonding and light cure. restoration.

Fig-5.10 Complete

6. AMALGAM RESTORATION. 6.1 Amalgam Restoration Materials. After the cavity has been prepared and the liners and base has been placed, the tooth is ready to be restored. One of the most common restorative materials is dental amalgam., which has been used for many years, dental amalgam is an effective, long lasting, and comparatively inexpensive restorative materials. Amalgam is a combination of an alloy with mercury. An alloy is a combination of two or more metals.

Fig-6.1 Mercury Spill Kit. Amalgam Capsules

Fig-6.3 Kerr amalgamators. amalgamator.

Fig-6.5 Activating the amalgam timer. amalgam carrier.

Fig-6.7 Placing amalgam scrapes materials. in a sealed container.

Fig-6.9 Matrix Band. (U/left, L/right).

Fig-6.2 Example of

Fig-6.4 Placing capsule in the

Fig-6.6 Loading an

Fig-6.8 Amalgam bonding

Fig-6.10 A (U/right, L/ left), B

6.2 Class I amalgam restoration 6.2.1 Armamentarium. 6.2.1.A Tray setup. • Mouth mirror • Explorer • Tweezers • Periodontal probe • Hatchet • Gingival marginal trimmer. 6.2.1. B Cavity preparation • Contra-angle slow speed hand piece. • Burs- stainless steel (SS), tungsten carbide (TC), diamond burs. 6.2.1.C Condensation and curving • Amalgam carrier • Amalgam condenser • Carver • Ball burnisher • • • • • • • •

6.2.1.D Finishing and polishing Multifluted SS finishing burs- variety of shapes Finishing stones- variety of shapes Bristle brush Rubber cup Cotton roll Dappen dishes Flour of pumice Whiting

6.2.2 Class I cavity The occlusal carious lesion begin in the area of pit and fissure where bacterial plaque is free to attack the inaccessible and poorly fused enamel ridges. Access to the lesion can be initially opening into the dentine through the most affected portion of the tooth. Cavity preparation is extended to all defective pit and fissures and into those areas that seems subject to future breakdown. 6.2,2.1 Outline form • Caries should be eliminated and rough outline of the cavity prepared. • Margins should be placed on sound tooth structure. • Conserve ridges involved in occlusal contacts whenever possible. • Include all defective pit and fissures. 6.2.2.2 Resistance form • Create flat pulpal floor (perpendicular to the long axis of the tooth). • Prepare wall that create 90 degree cavo-surface margins of enamel • Prepare wall that create 90-degree cavo-surface margins of amalgam. • Round all internal line angles. • Preserve adequate bulk of the mesial and distal marginal ridges. • Provide sufficient depth of pulpal floor occlusogingivally (1.5-2.0 mm) to resist fracture.

6.2,2.3 Retention form • Should create walls that are parallel to each other or converge occlusally. 6.2.2.4 Convenience form • The cavity should be of sufficient width to include the defect but otherwise as narrow as the available smallest plugger to allow sufficient condensation of amalgam. 6.2.2.5 Removal of remaining carious dentine • Removal of remaining carious dentine applies primarily to the caries in the deepest part (pulpally) of the preparation. • It may also include (where applicable), the elimination of any defective restoration left in the tooth after initial cavity preparation. • For exercise on frasaco teeth, this step is obviously unnecessary and cavity preparation depth is confined to 1.5 – 2.0 mm. 6.2.2.6 Finishing of enamel walls. • Remove all unsupported enamel rods. Unnecessary step in frasaco teeth except to remove any unsupported plastic at cavo-surface margin. • Smooth the cavosurface margins so that amalgam can be adequately carved and finished. 6.2.2.7 Features of the prepared cavities. • The outline for the cavity wall is placed halfway from the center of the defective pit, fissures and grooves (Fig-6.11). • A bucco-lingual width of 1.5 mm through the central groove and 1 mm in other extensions should place the wall in sound enamel and dentine (Fig-6.11). • The pulpal depth is measured 1.5 mm from the central fissure, desirably about 0.2 mm into dentine (Fig-6.12). A B

C Fig-6.11 A Initial caries, B Instrumentation , C Final

outline. D

Fig-6.11D Cavity outlines

Fig-6. 12

Cavity measurements. • The pulpal floor is flat and parallel to the occlusal plane of the tooth. • The depth of the prepared external walls is 1.5-2mm, depending on the cuspal inclines. • The prepared external walls (mesial, distal, lingual and buccal) are parallel to each other and perpendicular to the pulpal floor (Fig-6.13A). However, in some cases, the walls are prepared with a slight occlusal divergent (Fig6.13B).

Occlusal walls.

Fig-6.13A External walls.

Fig-6.13 B

• In the case where extension of the preparation ( to include fissure or caries ), becomes closer into the mesial and / or diatal marginal ridges, the preparation require slight tilting of the bur distally ( not more than 10 degrees ). This creates a slight occlusal divergent to prevent undermining the dentine support of the marginal ridge. • This principle is applicable when there is a limited distance between the proximal surface extensions to the marginal ridges. For premolar teeth, the distance should not be less than 1.6mm (figure-6.14). for molars, the minimal distance is 2 mm. direction of mesial and distal walls is influenced by remaining thickness of marginal ridges as measured from mesial or distal ridge. Mesial and distal wall should converge occlusally when distance from a to b is greater than 1.6 mm (left). If the distance is 1.6 mm or less, the walls must diverge occlusally to conserve ridge supporting dentine (right).

Fig-6.14 The direction of mesial and distal walls thickness. • The cavity should be of sufficient width to include the defect but as narrow as possible, realizing that it must be wide enough to permit instrumentation such as insertion and condensing of amalgam. • Occlusal outline covers all the primary grooves and is located in the middle 1/3 of the occlusal surface (Fig-6.15).

Fig-6.15 Primary grooves outline. • The mesial and distal margins should be parallel with the corresponding marginal ridges (Fig-6.16).

Fig-6.16 Mesial and distal margins parallel to marginal and oblique ridge. 6.2.3 Preparation cavity class I. • Pencil was used to defective grooves on the occlusal surface of the tooth. (Fig-6.17, Fig-6.18). • Place a jet 330 tungsten carbide bur, flat fissure diamond or a small round bur (size 1 or 2) in the hand piece ( jet 330 bur; present in both high and slow speed, SS round bur; in slow speed, fissure diamond; present both in high and slow speed). A B C Fig-6.17 A Pencil defective groove, B TC Jet 330, C Example of TC burs (Jet

330,245)

Fig-6.18 Pencil the defective

groove.

• Position the bur in the central fossa at right angle / perpendicular to the occlusal surface (Fig-6.19, Fig-6.20). • Enter the central pit with the bur and cut to just below the dentinoenamel junction approximately 1.5 mm (fig-6.21). Fig-6.19 Bur position Fig-6.21 Cut below serface.

Fig-6.20 Perpendicular to occlusal

dentinoenamel junction.

• Apply light intermittent pressure to avoid burning the tooth. • Remove the debris from the operating area with a gentle stream of air. • Move the bur along the fissures and grooves to obliterate the penciled defects maintaining the depth specified (2 mm) and keeping the bur perpendicular to the occlusal surface. • Maintain uniform depth of the pulpal floor. • Remove the enamel just short of the desired outline form. • Using bur in slow-speed hand piece, smooth the pulpal floor as well as preparing the facial and lingual walls to achieve parallelism (Fig-6.22). • All preparation walls must be parallel or 90 degree to the pulpal floor (Fig-6.23), except in the case where there is a limited distance between the proximal surfaces extensions to the marginal ridges as previously explained in 6.2.2.7. • Eliminate any sharp corners of the cavosurface outline (Fig-6.24) with the bur and remove any debris.

Fig-6.22 Achieve cavity wall. Eliminate corner 6.2.4

Fig-23 Pulpal floor.

Fig-6.26

Placement of lining or base.

• The use of lining / liner or base in cavity preparation becomes essential when the cavities finish deep in the dentine or when the cavities lie close to the pulp. Otherwise, placement of the lining or bases may be indicating as follow (Fig-6.25,26 and 27). Fig-6.25 Lining.

6.2.5 Restoration of cavity.

Fig-6.26 Varnish

Fig-6.27 Liner and Base.

6.2.5.A Trituration • The process includes the combining or mixing of liquid mercury with dry amalgam ally power. This process is carried out using amalgamators or amalgam triturators. The objectives are; 1. To coat each particle of alloy with mercury. 2. To begin the reaction that will produce a solid mass. • The required amount of amalgam is triturated with a 1:1 ratio of alloy and mercury in an amalgamator. • For trituration time, please follow the manufacturer’s instruction. • After the triturating is completed, empty the contents of the capsule onto the glass dish and begin the condensation immediately. • Nowadays, use of encapsulated amalgam alloy ready for trituration is recommended ( a weight, standardized amount of amalgam power and mercury sealed in a capsule). • The encapsulated products provide more consistent mixes of amalgam and are safer for use in the dental office. 6.2.5.B Condensation • Condensation is the processes of compressing and directing the dental amalgam into the tooth preparation with amalgam condensing instruments (condensers or pluggers) until the preparation is completely filled and then, overfilled with a dense of amalgam. • Proper condensation of amalgam promote; 1. Better adaptation of the amalgam to the walls of the preparation. 2. Elimination of voids due to compaction of the materials. 3. Reduction in the amount of residual mercury in the restoration. 4. Greater restoration strength. • Voids and increased residual mercury have been associated with weakened amalgam product thus reduce the strength of the restorations. • Adequate condensation techniques requires a significant amount of force to be applied to the condenser; 1. The force should be about 2-5 kg when using admixture amalgam. 2. For special amalgam, the force is considerably less, because heavy forces tend to push the spherical particles to the side and “punch through” the amalgam mass. 3. The size of the condenser end determines the amount of force to be exerted to the amalgam mass: the larger the end, the less force per unit area is applied. 4. Therefore, larger condenser must exert more force on the condenser to deliver adequate condensation pressure. 5. Amalgam should be condensed both vertically and horizontally or laterally (towards the walls of the preparation) (Fig-6.28).

Fig-6.28 Lateral and occlusogingival force to Properly condense amalgam. • When amalgam is condensed, mercury is brought to the surface creating a mercury-rich amalgam on the surface. • To reduce the amount of mercury left in the restoration (residual mercury), the preparation is overfilled, and the mercury excess is carved off. • The lower the residual mercury left in the restoration, the higher its strength.

Condensation procedure. • This condensation procedure must be completed within three to four minutes from the start of trituration. • If the amalgam is not used within this time, the remaining mix should be discarded and a new mix prepared. • Fill the smallest end of the amalgam carrier with the triturated amalgam. • Holding the carrier like a pen, pick up the amalgam by pushing the carrier into it (Fig-6.29). • Inject one-half of the amalgam in the carrier into the prepared cavity (Fig6.30). • Use the smaller end of the no.1 small round condenser to pack the amalgam into the cavity (Fig-6.31). • Start condensation in the central pit area, directing the condenser at right angle to the pulpal floor while exerting firm force on the amalgam to pack it onto the floor and into the line angle. • In condensing amalgam, always be sure to use a condenser that fit the cavity and to exert firm pressure on the amalgam. The condenser must be able to reach the pulpal floor in all parts of the cavity (Fig-6.31 to Fig-6.33). Fig-6.29 Picking up the amalgam. Fig-6.31 Condensing

Fig-6.32 Incorrect condenser.

Fig-6.30 Inject amalgam. Fig-6.33 Correct condenser

•

Firm condensation pressure is necessary in order to;

1. 2. 3. 4.

Remove excess mercury from the mix, Push the alloy particles together to mark a dense filling. Adapt the amalgam to all part of the cavity. Remove voids in the amalgam.

• Remove the mercury-rich surface from the amalgam with the condenser. • Continue adding and condensing small increment of amalgam until the cavity preparation is filled and all portions of the amalgam are thoroughly condensed. • Add additional amalgam and use the larger end of the round condenser to overfill the cavity. • Condensed the excess amalgam beyond the margins and the final contour. In this case, the surface of residual mercury will be carved away (Fig-6.34). Fig-6.34 Condensing excess.

6.2.5.C Burnishing. • After it is condensed with amalgam condenser, amalgam should be further condensed with a large burnisher, such as an ovoid (football) burnisher. This called “precarving burnishing”. • This should take place immediately after completion of condensation. • Apart from aiding condensation, burnishing is the first step in shaping the occlusal surface of the restoration.

Procedure of burnishing. 1. Using the ball furnisher with firm hand pressure, burnish the amalgam from the central sulcus to the margins. 2. This burnishing will draw the excess mercury into the over packed amalgam, which will be removed during carving procedure ( Fig-6.35 and Fig-6.36). 3. After carving is completed, the margins may be burnished again with light hand pressure to remove any roughness or flash remaining, thus ensuring a better marginal integrity (Fig-6.37).

Fig-6.35 Burnishing. roughness.

Fig-6.36

Remove excess

Fig-6.37

Remove

Mercury.

6.2.5.D Carving • Should begin immediately after condensation and precaving burnishing. • May be carved with any bladed dental instrument that has sharp edge. Most commonly used instruments are cleoid-discoid carver, Hollenbach or H carver (some may find spoon excavator useful for amalgam carving). • Most amalgam carving is perfomed using pulling strokes. Pushing strokes can be advantageous in developing occlusal anatomy (grooves). • Small class I and class II should be carved with enamel surface as a guide. • The carver should rest on the enamel adjacent to the preparation and be pulled in a direction parallel to the margins of the preparation. • When a stroke perpendicular to the margin of preparation is needed, carver should be pulled from enamel to amalgam. Procedure Amalgam carving 1. Remove the bulk of the over packed mercury rich amalgam with the large carver (Fig-6.38). 2. Carve from distal to mesial, resting a portion of the blade on the adjacent tooth structure (Fig-6.39) to lessen the chances of removing too much amalgam ( Fig-6.40). 3. Remove the excess amalgam shaving from the occlusal surface with a genetic stream of air. 4. Develop the occlusal anatomy of the restoration with a carver. Carve along the margins, resting the side of blade on the inclines of the cusps (Fig-6.41). 5. Keep the point of the carver centered between the margins of the restoration and use short, light strokes to carve the amalgam. 6. This will reestablish the desired contours and grooves and will avoid thin and weak margins (Fig-6.42) 7. Examine the carving with a carver and remove any thin layer or flash of amalgam that extends out over the enamel surface. 8. The amalgam must be carved back to the cavity margins to prevent subsequent fracture at the margins. 9. Lightly wipe the occlusal surface with a cotton roll to remove any particles of amalgam.

Fig-6.38 Remove excess

Fig-6.39 Carving guide

Fig-6.40 Carving

Fig-6.41 Develop occlusal anatomy centered

Fig-6.42 Carver

6.2.5.E Checking occlusion • Occlusion is checked when the carving appear to be correct. • This is accomplished with an articulating paper that marks the contact when the maxillary and mandibular teeth are brought together. • A piece of articulating paper is placed over the restoration and the patient is instructed to close his / her mouth very lightly to check if the occlusion is correct. • Remember to advise the patient not to bite too hard because of the danger of fracturing the restoration, which is weak at this stage. • Amalgam that has not been carved adequately will have “high spot” present on its surface, which should then be removed by additional carving. • It is important to check the occlusion before the amalgam becomes hard as the adjustment of occlusion with hand instrument becomes difficult once the amalgam has set. • The process of light closure with articulating paper is repeated, and additional carving is accomplished until the teeth can be closed to prerestoration occlusion. 6.2.5.F Finishing and polishing Finishing of an amalgam restoration includes evaluating the restoration for problems and correcting those, to ensure margins are even and contours and occlusion are correct as well as smoothing the restoration. Polishing is defined as smoothing the surface to a point of high gloss or luster. Allow at least 24 hours for the amalgam process to be completed before polishing the restoration. • Begin any necessary finishing procedure by marking the occlusion with articulating paper and evaluate the margin with an explorer. • If the occlusion in to be improved, white or green stone can be used to correct the discrepancy. • The area may be further smooth using light pressure with a suitably shaped finishing bur (Fig-6.47). The bur should be held perpendicular to the margin to guide the bur and prevent UN necessary amalgam removal (Fig-6.43). • Then, margin is re-checked with the explorer (Fig-6.44). Fig-6.43 Eliminate discrepancies.

Fig-6.44 Check with

explorer. • If the grooves or fossa is not adequately defined, a small round bur may be used to define the grooves. • Polishing procedure is initiated by using a course, rubber abrasives point at low speed and air-water spray to produce a smooth, satiny appearance of an amalgam surface. It is crucial to use rubber point at slow speed as the points disintegrate and can elevate the restoration / tooth temperature if used in high speed. • If amalgam surface does not exhibit smooth, satiny appearance after polishing, the surface is probably still rough. Then, resurfacing with a finishing bur should be repeated.

• When the surface of the amalgam is moderately polished with no scratches present, a high polish can be imparted to the restoration with a series of mediumand fine grit abrasive points. • As an alternative to rubber abrasive point, final polishing can be accomplished using a brush with flour of pumice and finally, with the rubber cup.

Final Polish.

Fig-6.45 Brush Polish.

Fig-6.46

Fig-6.47A Multifluted finishing burs (Stainless steel).

Use for smoothing the surface and enhancing the anatomy and marginal Adaptation of amalgam/restorative materials. Fig-6.47 B Outline form of various class I

preparation.

6.2.6 Practical cavity class I. 1. 2. 3.

36 Buccal pit, 36 Occlusal ( Entire fissure involved) 25 Occlusal (Central fissure only) 17 Occlusal (Oblique ridge preserved)

PRACTICAL SESSION 1. INSTRUCTION:

Buccal pit amalgam on 36

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures maintain -marginal ridges maintain PRACTICAL SESSION 2. INSTRUCTION: Date:…………………….

Class I amalgam on 36 (include all fissure)

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures maintain -marginal ridges preserved

PRACTICAL SESSION 3. INSTRUCTION:

Class I amalgam on 25 (central fissure only)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form

-convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures maintain -marginal ridges preserved

PRACTICAL SESSION 4. INSTRUCTION:

Class I amalgam on 17 (marginal ridge preserved)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary

Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures maintain -marginal ridges preserved PRACTICAL SESSION 5. INSTRUCTION :

Buccal pit amalgam on 26

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures maintain -marginal ridges maintain

6.2.7 Class I cavity with lingual/palatal extension. 6.2.7A. Armamentarium • 1. 2. 3. 4. 5. 6.

Tray setup: Mouth mirror Exploer Tweezers Periodontal probe hatchet Gingival Marginal Trimmer

•

Cavity preparation:

1. 2. • 1. 2. 3. 4.

contra-angle slow speed hand piece burs; stainless steel(SS), Tungsten carbide (TC), and diamond burs Matricing: Tofflemire matrix retainer universal matrix band wooden wedges scissors plastic instrument

• 1. 2. 3. 4.

Condensation and carving: amalgam carrier amalgam condenser / plugger amalgam carver burnisher

• 1. 2. 3. 4. 5. 6. 7.

Finishing: multiflute SS finishing burs; variety of shapes finishing stones- variety of shapes bristle brush rubber cup cotton roll dappen dish flour of pumice

6.2.7B Preparation of class I with palatal extension • The occlusal preparation follows the principles for a class I cavity preparation. • The margins are halfway from the center of the defective grooves (Fig-6.48). • The occlusal portion of the occluso-lingual preparation has minial width to preserve adjacent tooth structure. • However, when the disto-lingual cusp is small, the occlusal portion of the occluso-lingual preparation is cut more at the expense of the oblique ridge. This

will avoid weakening the disco-lingual cusp (Fig-6.49). • The lingual portion of the occluso-lingual preparation is a box, which has a flat gingival floor / set, with the mesial and distal wall parallel with one another (Fig-50). Fig-6.48 Cavity margins 6.49 Cavity Shape. (A) parallel wall.

fig-

(B) Fig-6.50 (A)

Box shape lingual , (B) Flat seat and

• The extremities of the occlusal grooves and the portion of the wall adjacent to the marginal ridges are prepared at 95 degree to the pulpal floor. This result in a slight flare in this area (Fig-51) or the axial wall diverges occlusally. • This principle is indicated only when the distance between the mesial and / or distal axial walls of the preparation to the marginal ridge or to the buccal and /or lingual tooth surface is 1.6 mm or less for premolar and 2.00 mm for molar teeth. • If the distance are more than 1.6 mm for premolar and more than 2.00 mm for molar teeth (to the marginal ridge or to the buccal and / or lingual tooth surface and no extension is necessary to include a pit or fissure caries), the mesial and / or distal axial walls are prepared to converge occlusally. This principle has been previously described for better understanding. • The pulpal floor of both preparations is flat in dentin. • The axial wall of the occluso-lingual preparation is flat, in dentin, and at a slight obtuse angle to the pulpal floor (Fig-6.52). Fig-6.51 Occlusal view Fig-6.52 Axial wall view

6.2.7C Measurement of prepared cavity Fig-6.53 Occlusal view Measurements

Fig-6.54 Cavity depth

Fig-6.55

6.2.7 D Procedure of cavity preparation • Pencil the defective grooves on the occlusal and lingual surface of the tooth as illustrated (Fig-6.56). • Enter the penciled occlusal lesion with the bur in the high or slow-speed hand piece. • Position the bur perpendicular to the occlusal surface and with light and intermittent pressure; penetrate to depth of approximately 1.5 mm. this will establish the level of the pulpal floor (Fig-6.57). • Remove the debris from the operating area to increase visibility. Maintaining the depth specified and holding the bur perpendicular to the pulpal floor, move the bur along the grooves to obliterate the penciled defects.

•

Create and maintain a flat pulpal floor (Fig-6.58).

Fig-6.56 Pencil the groove. Cavity depth.

Fig-6.58 Flat pulpal floor. Direction of cut

Fig-6.57

Fig-6.59

• Enter the occlusal portion of the penciled occlusal-lingual lesion with the bur to establish the depth of the pulpal floor (again 1.5 mm). then move the bur facially to prepare the distal pit area of the preparation. • This cut should be slightly more at the expense of the oblique ridge to avoid weakening the small disto-lingual cusp. • Move the bur lingually at the proper depth along the occlusal groove until the bur has cut through the lingual surface (Fig-6.59). • Position the bur parallel to the lingual surface at the lingual groove and begin preparing the lingual step with the side of the bur (Fig-6.60). • This will produce a cut that is deeper toward the occlusal (2.0 mm) than at the gingival (1.5 mm), resulting in an axial wall entirely based in dentin. • Extend the lingual box gingival to the termination of the lingual groove. • Do not make the cavity wider than the width of the bur or extend the pulpal floor deeper than previously indicated. • Finish the occlusal portion of the occluso-lingual preparation with the bur, flaring only the distal extremity of the groove and the portion of the wall adjacent to the marginal ridge if the distance is 1.6 mm or less (Fig-6.61,62). Otherwise, the axial walls are prepared at least parallel to the pulpal floor or slightly converge occlusally.

Fig-6.60 Bur position portion finished

Fig-6.61 Occlusal view.

Fig-6.62 Occlusal

• Position the bur perpendicular to the lingual surface and with the end of the bur flatten the axial wall, while using the side of the bur to prepare parallel mesial and distal wall (fig-6.63). • Use the end of the bur to flatten and finish the gingival wall. • The gingival wall must meet the tooth surface at a 90-degree angle. • A flat gingival seat at the lingual extension is desirable for resistance form. • The retention form of the lingual extension is accomplished by cutting retention grooves or locks with the side of the bur. • Grooves are placed in dentin in both mesio-axial and disto-axial line angles. • Grooves are placed in dentin in both mesio-axial and disto-axial line angles. • Grooves taper occlusally and terminate at the level of the pulpal floor (Fig-6.63). • Finish the mesial and distal wall of the lingual step with the enamel hatchet, using a planning-scarping action (Fig-6.64)

Fig-6.62 Flatten axial wall

Fig-6.63 Retention grooves.

Fig-6.64 Finish with enamel hatchet. 6.2.7 E Matricing Preparations with missing wall such as in the case of occluso-palatal/lingual and Class II require the use of a matrix to confine the restorative material during placement. The purpose of the matrix is to: • Substitute for missing walls so that adequate condensation forces can be applied • Allow re-establishment of contact with the adjacent tooth • Restrict extrusion of the amalgam and formation of an overhang at the interproximal margin • Provide adequate physiologic contour for the proximal surface of the restoration • Impart an acceptable surface texture to the proximal surface, particularly the contact area that cannot be carved and burnished. The most commonly used matrix in the United States is Tofflemire system. Others Type of matrix systems available are Squiveland, Auto-matrix and Palodent Matrix (held in place by Bitine ring). A. Tofflemire matrix •

Two type : straight and contrangle ( Fig-6.65) Fig-6.65 Shows the two types of Tofflemire

matrix. • 1. 2. 3. 4. 5. 6.

Consist of 6 main components: (Fig-6.66, 67, 68, 69). Locking nut Adjusting nut Retaining screw Vise Head Matrix band (which goes into the vise and head).

Fig-6.66 Parts of a retainer.

Fig-6.67 Parts of the Toffiemire retainer.

Fig-6.68 Occlusal and gingival edge of the band. holder

Fig-6.69 Vise slot of matrix

B. Matrix band placement • Turn the locking nut on the matrix retainer counterclockwise to free the retaining screw from the slot on the vise (Fig-6.66) • Position the Tofflemire retainer with the head up and the slot in the vise and the head facing you (Fig-6.67). • Form a loop with the matrix band and line up the end of the band. The edge of the band, which is toward the gingival, forms a smaller circumference than the occlusal side (Fig-6.68) • With the occlusal edge of the band facing the slot, insert the band into the vise so that the band ends are adjust visible at the end of the vise slot (Fig6.69). • The loop of the band may extend from the head of Tofflemire retainer in one of three directions (1) straight, (2) left, (3) right (Fig-6.70). Fig-6.70 The loop of the band extension. • With the retainer head up and the slot facing you, thread the band into the head and out through the right slot for application on a maxillary right tooth and mandibular left. • For application on a maxillary left tooth and mandibular right, thread the band through the left slot. • Turn the locking nut clockwise to secure the band in the retainer (Fig6.71A, B). • Place the band on the tooth, with the retainer on the facial side (Fig6.72).

(A) (B) Fig-6.71 (A) Mandibular left, (B) Maxillary right.

Fig-6.72 Placement of bend on the tooth

gingival

Fig-6.73 The slot in the head of matrix directed to

Fig-6.74 The slot in the head of matrix directed to occlusal. • The band must be assembled with the slot in the head directed gingivally, not occlusally (Fig-73). • Make sure that the band covers the gingival margin of the cavity preparation. • Turn the adjusting nut on the retainer clockwise until the band fit snugly. • To avoid injury to the gingival and the periodontal fibers do not overseat the band.

6.2.8 F Restoration of palatal extended class I cavity. A. TRIRURATION • Prepare as describe in previous section 5.2.5 A in class I amalgam restoration. B.

CONDENSATION

• Follow procedure described in previous section 5.2.5 B for condensation on the occlusal surface. • Inject a small increment of amalgam into the lingual step portion of the occluso-lingual cavity and use the small end of the condenser to pack the amalgam into the lingual step. • Direct the condenser gingivally and laterally while exerting firm force on the amalgam to thoroughly condense it along the mesial, distal, and gingival margins. • Continue to add and condense small increments of amalgam until the amalgam is condensed along the entire length of the mesial and distal margins of the lingual step. • Add and condense small increments of amalgam to fill the occlusal portion of the cavity. • Use the small end of the round condenser to pack the amalgam into this area (Fig-6.74). • Use the larger end of the condenser to over pack the cavity with additional amalgam. • Lateral condensation of amalgam toward all walls will improve adaptation (left) and overfill should be condensed with a large condenser (right) (Fig-6.75).

Fig-74 Use small condenser. condenser.

Fig-6.75 Use large

C.

BURNISHING

•

Follow the same procedures as described in the previous section 5.2.5 C.

D.

CARVING

• Remove the excess amalgam inside the matrix strip with an explorer. This will lessen the chances if fracturing the amalgam when the strip is removed (Fig6.76).

Fig-6.76 Remove excess amalgam. • Turn the locking nut the matrix retainer counterclockwise to release the matrix band from the retainer. Remove the retainer in an occlusal direction (Fig6.77). • Remove the matrix band from the tooth (Fig-6.78).

• Remove the bulk of the over packed and burnished mercury- rich amalgam from both restoration with the caver. • Carve along the margins, resting a portion of the blade on the adjacent tooth structure (Fig-6.79). Fig-6.77 removal of retainer.

Fig-6.78 Remove matrix band. along margins.

Fig-6.79 Carve

• Remove the amalgam shaving from the tooth with a gentle stream of air. • Develop the anatomy of the occluso-lingual restoration with a carver. • Keep the point the carver more toward the distal to reestablish the desired groove (Fig-6.78, 79). • Develop the anatomy of the occlusal restoration with a carver. • Carve along the margins, resting the side of the blade on the inclines of the cusps. • Maintain the point of the carver centered between the margins th reestablish the desired contours and grooves. Remove any thin layer of amalgam that extends out over the enamel surface. • Lightly wipe the occlusal and lingual surface with a cotton roll to remove any particles of amalgam.

Fig-6.80 Position carver.

Fig-

6.81 Develop anatomy. E.

CHECKING THE OCCLUSION

• Follow the same procedures as described in previous section 5.2.5 E. • Examine the restoration for high spots. Reduce any high spot with additional carving.

F.

FINISHING AND POLISHING

•

Follow the same procedures as described in previous section 5.2.5 F.

6.2.9 Practical class I cavity with lingual/palatal extension. 6.2.9A Class I with palatal extension on 17

PRACTICAL SESSION 1. INSTRUCTION: Class I amalgam with palatal extension on 17 Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE

COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures preserved -marginal ridges preserved

6.3 Class II small and medium amalgam restoration. 6.3.1 Armamentarium Basic tray setup 1. 2. 3. 4.

Mouth mirror Explorer Tweezers Periodontal probe

Cavity preparation 1. 2. 3. 4.

Contra-angle slow speed hand piece Burs Enamel hatchet Gingival marginal trimmers

Matricing 1. Tofflemire matrix retainer 2. Universal matrix band 3. Wedge and wood

Condensation and carving 1. Amalgam carrier 2. Condenser 3. Carvers Finishing and polishing 1. 2. 3. 4. 5. 6. 7. 8. 9.

Finishing burs Green and white stone Fine and extra-fine cuttlefish disks Rubber point Rubber cup Bristle brush Dappen dishes Flour of pumice Proximal strip

6.3.2 Preparstion of class II cavity on lower molar (MO). • This preparation combines the features of an occlusal cavity and the proximal box. • The occlusal margins of the preparation starts from the center of the defective grooves, fissures and pits. • The walls are parallel to one another and are perpendicular to the pulpal floor as noted in (Fig-6.82 ). • However, in some cases, the walls are prepared with a slightocclusal divergent or flare (Fig-6.83). • In some cases where extension of the preparation (to include fissure or caries), becomes closer into the mesial and/or distal marginal ridges, the preparation require slight tilting of the bur distally (not more than 10 degrees).This creates a slight occlusal divergent to prevent undermining the dentin support of the marginal ridge. • This principle is applicable when there is limited distance between the proximal surfaces extensions to the marginal ridge as previously described in “features of the prepared cavities”. • The occlusal view shows that the facial and lingual walls of the proximal box are extended into their respective embrasures only enough to be free of contact with the adjacent tooth. These walls diverge slightly to meet the tangent to the mesial surface at a 90 degrees angle (Fig-6.84). • The mesial view shows that the lingual wall of the proximal box is parallel or to the long axis of the tooth. • The facial walls approximately parallel or to the facial surface (Fig-6.85). • The gingival wall is flat and perpendicular to the long axis of the tooth. • The pupal floor is flat in dentin, and parallel to the occlusal plane of the tooth (Fig-6.86). • The axial wall is parallel to the long axis and curves slightly to follow the facio-lingual curvature tooth. This wall is in dentine (Fig-6.87). • The axio-pulpal line angle is beveled. Any unsupported enamel is removed from the gingivo-cavosurface (Fig-6.87, 88). • There are retentive grooves in the lingo-axial and facio-axial line angles. These grooves in the dentine only and follow the facio-lingual curvature of the axial wall (Fig-6.89).

view

view.

Fig-6.82 Outline form

Fig-6.83 Occlusal

Fig-6.84 Ficial and lingual wall

Fig-6.85 Mesial

Fig-6.86 Gingival and pulpal floor position. position.

Fig-6.88 Beveled angle. retentive grooves. Measurements of Class II cavity

Fig-6.87 Axial wall

Fig-6.89 Linguo-axial & fasio-axial

(in mm)

Fig-6.90 Occlusal view

Fig-6.91 Mesial view

Fig-6.92 Cross-sectional view 6.3.3 Some examples of common class II cavity features and molars. Fig-6.93 Slot on M & D 6.95 MOD Fig-6.96 DO preparation distowith distal pit -palatal extension.

Fig-6.94

in maxillary premolars

MO & DO

Fig-6.97 MO distal pit

Fig-

Fig-6.98

MO with

with marginal ridge.

Fig-6.99 DO with mesiocclusal fissure.

Fig-6.100 MOD preparation.

6.3.4Procedure of cavity preparation • Pencil the defective grooves on the occlusal surface of the tooth (Fig-6 101 ). • With articulating paper, record the occlusal contact of the opposing tooth. • Modify the outline form so that the margins of the preparation do not lie on a contact area.

• Enter the pit nearest the involved proximal surface with a no.245 as illustrated. • Proximal, the long axis of the bur and the long axis of the tooth should remain parallel during the cutting procedures. • Ass the bur approaches the distal pit, the proper depth (one-half thirds the length of the cutting portion of the bur),which just exposes dentin, should be established (approximately 1.5 mm) (Fig-6.102 ).

Fig-6-101 Pencil defective grooves

bur tilted crown to twothe

Fig-102 Burs

position. • Remove the debris from the operating area with a gentle stream of air. • Move the no.245 bur distally along the depth specified and keeping the bur perpendicular to the occlusal surface. • Extend the cut toward the mesial to obliterate the penciled defects. As you approach the marginal ridge, direct the cut toward the center of the contact area. Do not break through the mesial marginal ridge at this time (Fig6.103 ). • Use the bur in a hand piece as a guide for determining the occlusogingival depth of the preparation. • With the bur stationary, hold it vertically next to the mesio-facial surface of the tooth so that the tip of the bur is 0.5 mm below the contact area. • This is where the gingival wall will be. Note how much of the bur must penetrate the tooth to reach the desired level of the gingival wall (Fig-6.104 ). Fig-6.103 Marginal ridge Fig-6.104 Occlusogingival depth. • With the no.245 bur, start the end of the bur cutting along the exposed proximal dentinoenamel junction, two third at the expense of the dentin and onethird at the expense of the enamel. • Need to ensure that the bur’s long axis is approximately parallel to the long axis of the tooth crown, but tilted slightly to the distal. • With the pressure directed gingivally and slightly towards the mesial to keep the against the proximal enamel, pendulate the bur facially and lingually along the dentinoenamel junction. • Because the dentin is softer and cuts easier than the enamel, the bur should be held against the harder enamel to guide and create an axial wall that follows the outside contour of the proximal surface. • The mesio-distal width of the completed proximal ditch cut should be onethird in enamel and two-thirds in dentine. • When the proximal ditch cut is all in dentine, the axial wall often is too deep. Because the proximal enamel becomes less thick from occlusal to the gingival, the end of the bur will come closer to the external tooth surface as the cutting moves gingivally. • The proximal ditch cutting is diverged gingivally so that the facio-lingual dimension at the gingival will be greater that at the occlusal (Fig-6.105, 106, 107). • Do not remove all of the proximal enamel but leave a thin shell of enamel in this area to protect the adjacent tooth from contact with the bur. • Break out the thin remaining proximal enamel with the enamel hatchet, using it as lever to fracture the enamel. • Finish the facial, lingual, and gingival wall of the proximal box with the enamel hatchet using a planning-scraping action (Fig-6.108, 109 ).

seat position.

the wall.

Fig-6.105 Proximal depth.

Fig-6.106 Gingival

Fig-6.107 Occlusal convergence.

Fig-6.108 Finishing

Fig-6.109 Finishing with planning-scraping action. • With the gingival margin trimmer, from a slight bevel at the axio-pulpal line angle (Fig- 6.110). • With the same instrument, sweep across the gingivo-cavosurface to remove unsupported enamel rods and cause a slight rounding of the facio-gingival and linguo-gingival line angle (Fig-6.111, 112).

Fig-6.110 Bevel axio-pulpal line angle carvosurface

Fig-6.111 Bevel gingivo-

margin.

• With the no.169L (TC) or tapered diamond bur in the slow-speed hand piece, cut a retentive groove in the linguo axial line angle (Fig-6.113 ). • Begin at the lingo gingivo axial point angle and used only the tip of the bur drawing it occlusally (in the dentin only). • The groove should be about 0.5 mm deep at gingival and gradually fade towards the occlusal (Fig-6.114 ). • Avoid placing the groove entirely at the axial dentinal wall. Remember that the curvature” of the axial wall. In addition, beyond the height of the pulpal floor”. • Use the same method described in the in the fascio-axial line angel.

Fig-6.112 Line angle rounded.

the expense of either the lingual or groove must “follow the facio-lingual the groove “must not extend occlusally previous step to cut a retentive groove

Fig-6.113 Groove placement.

Fig-6.114 After groove placement.

6.3.5A Figures of class II on second premolar (MO) Fig-6.115 Visualization of proximal preparation. Proximal box.

Fig-6.116

Fig-6.117 Mesial wall fractured off using hand instrument.

Fig-6.118 Undermined proximal enamel removed using hatchet. Fig-6.119 Beveling axiopulpal line angle. Fig-6.120 A.Bevel enamel portion of gingival wall using gingival marginal trimmer, B&C. Round off linguogingival and buccogingival corners by rotational sweep with gingival marginal trimmer. 6.3.5B Figures of class II on first premolar (MO) Fig-6.121 A. Two surface preparation, B.Occlusal view, C. Proximal view. Fig-6.212 Compare the difference between 34&34 in size of pulp chambers, lingual cusps direction of pulpal walls. 6.3.5C Figures of class II on second premolar (MOD).

Fig-6.213 MOD preparation of second premolar. Fig-6.124 MOD cavity of first premolar.

6.3.5D Figures of class II cavity preparation on maxillary first molars.

Fig-6.125A. MOD Caries of first molar. molar.

Fig-6.125B M&D restoration on

Fig-6.126 A.Conventional MO preparation, B. MO preparation extended to distal pit, C. MOL preparation distal pit and oblique ridge, D. MO with buccal fissure extension.

6.3.5E Figure of class II cavity on mandibular fist molar.

Fig-6.127A. MOD preparation on MOD amalgam mandibular first molar. restoration on mandibular molar. Fig-127C. MOD cavity with lining. molar

Fig-6.127B.

Fig-127D. MOD restoration on

replaced one lingual cusp. 6.3.6 Matricing • Thread the band into the retainer head. Then turn the locking nut clockwise to secure the band in the retainer. • Position the retainer head is facing you. Form a loop with matrix band and line up the end of the band. Rest the band on a paper pad and with a ball burnisher contours the proximal area of the band about 1 mm from the edges. • Place the band on the tooth; make sure that the band covers the gingival margin of the cavity preparation. • The band must be wide enough gingivo-occlusally to provide a wall along the entire length of the proximal box. Ideally it should extend about I mm above the adjacent marginal ridge, but not higher. If necessary, trim the band with a scissors to obtain correct dimensions. Turn the adjusting nut on the retainer clockwise until the band fits snugly (Fig-6.128).

Fig-6.128 A Placed the matrix band.

Fig-6.128B

Placed the strip, band and wedge.

Fig-6.128C Band placement. • To avoid injury to the gingival and the periodontal fibers, take care not to force the matrix band too for gingivally. • Shape the wedge with carver to fit it to the mesial gingival embrasure form. Insert the wedge from the lingual into the mesial embrasure as far as it will go with a tweezer. • Recontour the band with the ball burnisher to establish close contact between the band and the adjacent tooth. A cavity base is placed as stated in class I if indicated. Fig-6.129 Shown the correct placement of matrix band.

6.3.7 Restoration on class II cavity. 6.3.7A Trituration. Prepare a previously described for class I. 6.3.7B Condensation. • Fill the carrier with the triturated amalgam. Inject one half of the amalgam in the proximal box. • Use a small end of the founded diamond shaped condenser to pack the amalgam into the proximal box. • Direct the condenser gingivally and laterally while exerting firm pressure on the amalgam to thoroughly condense it along the facial, lingual and gingival margins and into the retentive grooves. • Remove the mercury rich amalgam with the large end of the condenser. Continue to add and condense increments of amalgam until the amalgam is condensed along the entire length of the facial and lingual margins of the proximal box. • Add and condense small increments of amalgam to fill the occlusal portion of the cavity. Use the small end of round condenser to pack the amalgam into the area. (Fig-6.130). • Add additional amalgam and use the large end of round condenser to over pack the cavity, condensing the excess amalgam well beyond the margins and final desired contour.

Fig-6.130 Amalgam condensation.

6.3.7C Burnishing. •

Burnish all accessible occlusal margins.

6.3.7D Carving. • With an explorer, remove the excess amalgam inside the occlusal opening of the matrix band. Roughly carved the restorations which will lessen the chances of fracturing the amalgam when the strip is removed and to reduce the level of the marginal ridge area to that of the adjacent tooth (Fig-6.131). • Remove the wedge with a tweezers. • Then turn the locking nut on the matrix retainer counterclockwise to release the band. • Remove the retainer from the band in an occlusal direction. • Carefully withdraw the matrix band first from the opposite proximal surface. • Do not lift the band directly toward the occlusal because this will tend to fracture or dislodge the unset amalgam. • Remove the excess amalgam at the gingival margin and shape the gingival embrasure with the interproximal carver, using the remaining tooth structure as a guide. Insert the carver first from the facial and then from the lingual and curve along the entire length of the gingival margin, take care not to flatten this

area. • Use a carver to remove the excess amalgam from the facial and lingual proximal margins and to contour the facial, lingual, and occlusal embrasures. • Carve along the margins in an occlusal direction resting the blade on the adjacent tooth structure (Fig-6.132). • Remove the excess amalgam from the occlusal surface with the discoid-cleoid carver. Carve along the margins from distal to mesial. • Begin developing the occlusal anatomy with the carver, guiding the tip of the carver to establish the occlusal contours and grooves over the marginal ridge (Fig-6.133). • Examine the restoration to make sure that no amalgam extends over the tooth surface beyond the cavity margins (Fig-6.134). • Lightly wipe the occlusal surface with cotton to remove any particles of amalgam. Fig-6.131 Remove excess amalgam.

Fig-6.132 Contour facial, lingual and occlusal embrasures.

Fig-6.133 Develop occlusal anatomy.

Fig-6.134 Examine restoration. 6.3.7E Checking Occlusion. • Examine the restoration for any high contact or high spot using articulating paper by closing the upper and lower jaw lightly on each other. • Reduce any high spots with additional carving with amalgam carver. • The process of light closure with articulating paper is repeated, and additional carving is accomplished until the teeth can be closed to prerestoration occlusion. 6.3.7F Finishing and Polishing • Allow at least 24 hour for the amalgam to harden thoroughly before polishing the restoration. • Smooth the facial and lingual margins and round the marginal ridge with the fine and extra-disks .If the margins were carved smoothly, the fine disk need not be used. • Using a slow speed and light, intermittent pressure move the disk gingivoocclusally along the margins and up onto the occlusal surface. A few revolutions with the disk should make the margins smooth (Fig-6.135). • Proximal strips can also be used to contour the proximal surface of the restoration. • “Avoid damaging the proximal contact” of the proximal contact of the restoration and “injuring the proximal gingival”. • Check the proximal margins with the explorer. There should be no catch of the explorer tin when passed in either direction across the margins.

Fig-6.135 A Finishing with fine disc. Fig-6.135B Abrasive-coated discs (Polishing discs).

Fig-6.135D Finishing instruments.

PRACTICAL CLASS Cavity Class II with Amalgam Restoration. 6.3.3 6.3.3 6.3.3 6.3.3

B DO on 46 C MOD on 35 D MO on 16 (preserve distal pit) E DO on 26 (preserve mesial pit)

Fig-6.135 C Mandrel (snap-on or screw-on).

PRACTICAL SESSION 1. INSTRUCTION:

Class II amalgam on 37 (MO)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures preserved -marginal ridges preserved

PRACTICAL SESSION 2. INSTRUCTION:

Class II amalgam on 46 (DO)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS

Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures preserved -marginal ridges preserved

PRACTICAL SESSION 3. INSTRUCTION:

Class II

amalgam on 35 (MOD)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used

-sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures preserved -marginal ridges preserved

PRACTICAL SESSION 4. INSTRUCTION:

Class II amalgam on 16 (preserve distal pit)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable)

Polishing -smooth and shiny -fissures preserved -marginal ridges preserved

PRACTICAL SESSION 5. INSTRUCTION: Class II amalgam on 26 (preserve mesial pit) Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -outline form -resistance form -retention form -convenience form -finish of enamel walls -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling and Carving -underfill / overfill -overhanging or deficient margin -maintain anatomy -maintain contact point (if applicable) Polishing -smooth and shiny -fissures preserved -marginal ridges preserved

6.3.2. Class II amalgam in clinical procedure. the tooth is

The tooth is prepared with dental handpieces and assorted burs. Once prepared, it is restored with dental amalgam.

Equipment and supplies (Fig-6.136 to Fig-6.138). • Basic setup: mouth mirror, explorer, cotton pliers. • Air-water syringe tip, HVE tip, and saliva ejector. • Cotton rolls, gauze sponges, pellets, cotton tip applicators, and floss. • Topical and local anesthetic setup. • Rubber dam setup. • High- and low-hanpieces. • Assortment of dental burs • Spoon excavator • Hand cutting instruments (hatches, chisels, hoes, and gingival margin trimmers). • Paper pad, cement spatula, and placement instrument. • Matrix retainer, matrix bands, and wedges. • Locking pliers or hemostat. • Amalgam capsules. • Amalgam well. • Amalgam carrier and condensers. • Amalgamator. • Carving instruments. • Articulating paper and forceps.

Fig-6.136 Amalgam procedure tray placed Setup armamentarium. retainer.

Fig-6.137 (A) Matrix band and wedge ( B ) Matrix band

Fig-6.138 Lining material. Procedure Steps. • Greet and prepare the patient for the procedure. Review the medical history. • Prepare for the administration of the topical and local anesthetic. • Placed the rubber dam (Fig-6.139 to Fig-6.141). • Prepared the cavity. • Placed the lining. • Placed the matrix band with retainer. • Prepared the amalgam capsules then placed the amalgam into the cavity and condensed the amalgam. • Carving and burnishing the amalgam. • After finishing the curving of the anatomy in the restoration, removed the matrix carefully. • Remove the rubber dam carefully. • Used the articulating paper and the check occlusion. • The restoration is wiped off with a wet cotton roll and to remove any blue mark left by articulating paper. Rinse the patient’s mouth thoroughly to clean any debris from the mouth. • The patient is cautioned not to chew on restoration for a few hours and dismissed.

Fig-6.139 Cavity being prepared by dentist.

Fig-6.140 Loaded carrier, ready for

use.

Fig-6.141 placing the articulating paper. 6.3

Class II complex amalgam restoration.

Fig-6.142 Complex (large) Cavity Fig-6.144

Complex MO

Fig-6.143 MO Complex. Fig-6.145 Complex MOD.

Fig-6.126 The complex cavity restored with amalgam restoration which protects the entire occlusal surface. Fig-6.147 The complex (large) cavity, length 5.5 mm, deep 2.5 mm Note: The cavity preparation, restoration of class II compound/complex large cavities should be follows as described as in preparation of class II amalgam restoration. 6.4

Class V amalgam restoration.

Class V carious cavities occur as a result of stagnation on the surface close to the gingival margin, more commonly on the buccal than on the lingual aspect. The cavity may frequently extend below the free gingival margin and if recession has occurred the carious area which may extend into the cementum and dentine if the root. The restoration of the class V cavities resembles in many ways that of class I, however some significant interesting differences. it is worthy of note that cavities in premolar and molar teeth, the use of reversed mirror head is a considerable help. This simple variation of the normal mouth mirror often gives better retraction of the cheek, reflection of light on the cavity, and a reflected view of the working field, with considerably greater case of manipulation.

teeth.

Fig-6.148

Eighteen years old amalgam restoration on anterior mandibular

Fig-6.149 Numerous stained class V caries lesions. Fig- 6. 150 A moderately deep, V-shaped cervical notch in a maxillary canine. 6.4.1 Cavity preparation The outline form of this type of cavity usual conforms to the general shape shown in Fig-6. The cavity preparation may be started in either one of two ways. Removal of carious tissue may be performed with an excavator or with a round bur No.4 or 5,

in a straight handpiece in preference to a contra-angle, where access permits. The bur should be used with light, circular, stroking movement. The completed cavity should be of uniform depth between 1.5 and 2 mm. The principles applying to the lining of this cavity are in all respects the same as in the case of the class I cavity. The contour of the floor is established in the same way. Enamel margins should be surveyed and smoothed with the enamel finishing bur, whilst at the same time establishing the 90-degree cavo-surface angle. The use of high-speed instruments in this type preparation is little difference in general technique. A fissure bur may be used from the outset through to the completion of preparation and the effective water spray provides a clear field. Lightness of touch and ease of control assist in avoidance of the gum margin. Fig-6.151 Outline form of may be used class V cavity on premolar amalgam restoration.

Fig-6.153 Class V restoration on dam to canine and premolar need to re restore. moister Fig-6.155 Cavity preparation custom matrix,

Fig-6.152 A hand instrument as a matrix for class V

Fig-6.154 Place the rubber control the bleeding and

Fig-6.156 A

stabilized with wedges to support amalgam placement. 6.4.2 Insertion of amalgam The cavity toilet completed and dry field obtained, the insertion of amalgam follows the same pattern as that described for class I cavities. Amalgam insertion starts in the normal manner when the cavity is two-thirds filled the matrix band is placed and condensation proceeds through the aperture previously made ,packing toward the cavity margin. A smooth, highly polished filling is perhaps of greater importance in the class V restoration. Care in curving to eliminate irregularities after condensation. Polishing proceeds as previously described and a rubber cup is used in place of the cup-shape brush and then completed final restoration.

Fig-6.157 Complete Amalgam Insertion amalgam.

7. COMPOSITE RESTORATION.

Fig-6. 158 Final Restoration with

Composite restoration known as tooth colored restoration. There is nothing more gratifying than the sight of an intact young anterior dentition in an adolescent or preadolescent patient, particularly the healthy, natural gingival-enamel relationship that is characteristically observed in young dentitions. Tooth-colored restorative materials have increasingly been used to replace missing tooth structure and modify tooth color and contour, thus enhancing facial esthetics. The search for an ideal esthetic material for conservative restoration has resulted in improvements in materials and techniques, particularly in recent years. Synthetic resins and the acid etch technique represent major advances. Adhesive materials that have strong bond to enamel and dentin further simplify restorative techniques. Cavity preparation technique for class III, class IV, class V, which is to be restored with direct tooth colored restorative materials, is covered this chapter. CLASS III CAVITY: • The cavity is a box formed by the incisal, facial, gingival, and axial walls (Fig-7.1). • Every attempt is made to maintain contact with the adjacent tooth with natural tooth structure (Fig-7.2). • Extension of the outline form is minimal. • Retentive grooves in the incisal and gingival dentinal walls are optional (Fig-7.5). • Positioning matrix band for class III cavity (Fig-7.6). • Various size and form of class III cavities (Fig-7.3, 7.4 and 7.7 to 7.10). Fig-7.1 Cavity shape. Maintain contact.

Fig-7.2

Fig-7.3 (A) Point of entry to class III preparation with Cavity in mandibylar canine , (B) Small retention. Preparation with cervical and mesial retention.

Fig-7.5 Cavity outline. Matrix band in position

Fig-7.4 Larger lingual lock

Fig-7.6

for class III. Fig-7.7 Larger class III cavity. cavity, a. from gual, b. from mesial aspects.

cavity.

Fig-7.8 Outline form of class III lin

Fig-7.9 Use of modified lingual lock as retention in large class III

Fig-7.10 a, The persistence of stain at the amelo-dentinal junction. B, The

appearance of stain at labio-cervical margin, deep to enamel.

Composite Restoration Materials Fig-7.11 Composite materials. Shade guide.

Fig-7.12

Fig-7.11 A Composites, Bonding, Etching,

Articulating

paper, and Dappen dishes.

Fig-7.11B Some brand of composite

materials.

Fig-7.11 E The instruments, materials, and equipment for composite restoration.

Class III composite restoration. 7.2.1. Tooth preparation for class III cavity. 7.2.1.1ARMAMENTTARIUM 1.

BASIC TRAY SETUP

Mouth mirror

2. Explorer 3. Tweezers 4. Periodontal probe

CAVITY PREPARATION 1. Contra-angle slow-speed hand piece 2. Burs 3. Enamel hatchet MATRICING

1. Mylar strip 2. Transparent wedges

MIXING AND PLACEMENT 1. Mixing pad 2. Acid etch 3. Unfilled resin /Bonding 4. Composite resin 5. Disposable mixing spatula 6. Plastic instrument FINISHING

1. 2.

Two sided finishing strips Twelve fluted carbide bur

7.2.1.2Cavity preparation • Pencil the lingual outline form on the tooth (Fig-7.13). • The contact area is not to be included in the final outline of the preparation. • Enter the lingual portion of the tooth near the center of the penciled area with the round bur in high-speed hand piece (Fig-7.14). • Hold the bur perpendicular to the lingual surface and move the hand piece gingivally and incisally to cut a trough. • Do not remove all of the proximal enamel but leave a thin shell of enamel in this area. Fig-7.13 pencil the outline

Fig-7.14

Entry point • With the bur in the slow-speed hand piece, smooth the axial wall and further develop the box form (Fig-7.15). • Avoid overextending the preparation facially and incisally. • It is better to leave an enamel contact with the adjacent tooth when possible. • Break out the remaining proximal enamel with the enamel hatchet, using it as a lever to fracture the thin enamel (Fig-7.16). • Use the enamel hatchet to smooth the incisal and gingival wall. • Plane the wall by carefully thrusting the instrument facially. • Maintain firm control of the instrument to avoid fracturing of the facial wall.

Fig-7.15 Develop box form 7.16Break proximal enamel

Fig-

• Smooth the facial and axial wall with the hatchet. • Rest the side of the blade against the axial wall and, with the end of the cutting edge, scrape the facial wall first incisally and then gingivally (Fig-7.17 ). • Clinically, when acids etch technique is being used; a 45-degree bevel along the cavosurface margin of the enamel is created. This bevel: 1. Increase the tooth surface area for acid etching. 2. Provides an area for unfilled resin tag penetration. • Clinical results of this additional step are: 1. Increased retention of the restoration. 2. Minimized abrupt visual change from the restorative material to the remaining enamel surface. 3. Decreased marginal leakage. • With the round bur in the conventional speed hand piece, cut a retentive groove at the expense of the dentine in the incisal dentinal wall (Fig-7.18). • The incisal groove should finish in the dentine only. Avoid undermining the enamel at the incisal corner. • Using the method described previously, create a retentive groove in the gingivo-axial line angle (Fig-7.19).

• The gingival groove may be slightly larger than the incisal due to the greater bulk of the dentin in this area.

Fig-7.17 Smoothen wall

Fig-7.18 Retentive groove placement. 7.19 After placement

Fig-

7.2.1.3 Features of class III cavity involving labial and palatal surface. Fig-7.20 Class III caries on lateral incisor of mesial aspect Fig-7.21 Class III caries on central incisor of mesial aspect. 7.2.1.4 Cleaning the tooth • Using a rubber cup I slow-speed hand piece, clean the enamel surface with slurry of flour of pumice and water mixed in a dappen dish. Clinically, this has the effect of removing bacterial plaque and salivary contaminants, and cutting debris and stain from the prepared cavosurface bevel and adjacent enamel. This procedure provides a clean surface that is more receptive to acid etching .Do not use paste-containing fluoride, as this will diminish the effect of acid etching. • Do not use paste-containing fluoride, as this will diminish the effect of acid etching. • Rinse the tooth with a water spray to remove the pumice. • Carefully dry the tooth with a gentle steam of air (do not over dry/ desiccate the dentin). 7.2.1 5 Lining / base application • Prior to acid etching, moderate and deeply exposed to protect the pulp tissue from:

dentin must be covered

1. The etching solution 2. The chemical irritation of the composite resin. • When a great amount of tooth structure has been lost due to caries or fracture, a base should be used underneath the restoration, Otherwise, lining the exposed dentin should be sufficient in protecting the pulp. • Materials for use as lining or base for tooth colored restoration has been described in “pulp protection”. • If the cavity is very deep and very close to the pulp ( that requires indirect pulp capping) or small, pin-point pulp exposure occur while doing cavity preparation ( that requires treatment with direct pulp capping), then, calcium hydroxide lining (e.g.; dycal ) need to applied on the tooth surface overlying the pulp. • Dispense a drop each of the catalyst and base pastes of the calcium hydroxide material on a paper-mixing pad (Fig-7.22). • Using the mixing instrument provide with the material, mix the catalyst and base together.

• Touch the tip of the mixing instrument to the paste and carry a small amount to the dentine to be covered. • Touching the instrument to the dentine will transfer the calcium hydroxide to it. • Apply to form a thin, uniform layer and allow the material to set. • Always remember that calcium hydroxide lining is placed overlying the pulp / close to the pulp, placement of a base above the calcium hydroxide layer is needed (using either conventional GIC such as Fuji IX or RM-GIC such as Fuji II LC ) before restoring the cavity with composite resin. This is to protect the calcium hydroxide layer from fracture as they become rigid after set. • Inspect the preparation to ensure dentine overlying the pulp has been covered with the calcium hydroxide. If not, repeat the previous mixing steps. • Lining / base should not extend beyond the DEJ onto enamel, as it will inhibit acid etching and subsequent bonding. • Excess lining / base is removed with an explorer or spoon excavator.

Fig-7.22 A Dycal, Mixing pad, gauge, dycal applicator.

Fig-7.22B Mixing dycal. dycal applicator

Fig-7.22C Mixed dycal with

7.2.1 6 Acid-etch technique • Dispense two to three drops of phosphoric acid solution (35 % to 37 % depending on manufacturer’s formulation Fig-7.23) into a plastic well or dappen dish. • Use a small brush or applicator, paint the enamel with the acid gently for 20 to 30 seconds (follow the manufacturer’s instruction). • Then, return the brush to the dispensed acid, and paint the enamel again with fresh etchant. • Be certain to coat the prepared enamel bevel as well as 4 to 5 mm of intact adjacent surface enamel. • Following the acid application, rinse the tooth thoroughly from all aspects with a water spray for 30 seconds. • With the air spray, dry the tooth carefully from all aspects to remove all moisture. The presence of any moisture on the enamel will interfere with the successful bonding of the resin. The etched enamel surface should exhibit a chalky white appearance (can be refer previously described etching technique).

Fig-7.23 Etching materials 7.2.1.7

Placement of unfilled resin / bonding

• Apply one drop of the unfilled resin into a plastic well (is also known to as intermediary resin, bonding agent and enamel bond).

• Mix the two drops together with a fresh applicator brush, and paint the unfilled resin over the etched enamel and protected dentine. • Be sure to paint the unfilled resin beyond the fracture line over the etched enamel surface (Fig-7.24). • The resin ensures wetting of and penetration into the etched enamel surface. This enhances retention and sealing of the composite resin. • The unfilled resin is then light cured for 10 seconds (Fig-7.25). . Fig-7.24 Applying the bonding.

Fig-7-25 light

curing. 7.2.1.8

Matricing

• Place a 1 ½-inch Mylar strip interproximally and secure it against the gingivo-cavosurface with an appropriate wedge (Fig-7.26). • If necessary, contour the matrix with a warmed large, round burnisher or contouring plier. • Test the final position of the strip by practicing your direction of pull, which will be used in the following procedure ( Fig-7.27 and 7.28). • The surface quality left by the mylar strip matrix cannot be surpassed by any finishing or polishing procedure.

Fig-7.26 Strip placement.

Fig-7.27

Check fit. Fig-7.28 The final position.

matrix

Fig-7.8 A Mesial cavity filled with composite, the strip held in position during setting.

7.2.1.9 Composite resin placement • Using a plastic instrument, insert the composite resin into the preparation taking care to avoid creating pockets of air or voids in the restoration. • The resin should be introduced into the cavity incrementally, with each layer less than 2 mm in thickness. This is to ensure good depth of curve and to reduce the polymerization shrinkage of the composite resin. • Avoid incorporating air voids into the matrix or preparation by slowly folding small amounts of the material into the most remote parts of the preparation (Fig-7.29). • Pack the composite resin using plastic instruments. It is desirable to use Teflon plastic instrument as compared to metallic plastic instrument because Teflon cause less scratching to the composite resin surface during packing or insertion. • Slightly overfill the preparation (Fig-7.30). • Pull the mylar strip to create a contour to the restoration that will require the least amount of finishing and polishing while ensuring good adaptation of the material to the cavity preparation (Fig-7.31).

• Remember that any further contouring or finishing will only decrease the surface quality. Fig-7.29 Material insertion. Slightly overfills.

Fig-7.31

Fig-7.31 Pull the strip to create contour. 7.2.1.10

Finishing and polishing

• With the fine carbide or tapered diamond bur in the high-speed hand piece, remove any gross marginal excess of material that resists flicking off with the explorer (Fig-7.32, 33). • Some of the burs that can be used are diamond bur L10 for contouring the labial surface and pear shape or F40 bur contouring the palatal surface and cingulum area. • White stone (tapered and round shape) can also be used to further contour the labial and palatal surface of the restorations. • The proximal surface can be contoured using an inter proximal finishing strip that has two abrasive surfaces (fig-7.34).

Fig-7.32 lingual view Remove marginal excess.

Fig-7.33

Fig-7.34 finishing with strip.

• Pass the strip through the contact from the incisal aspect. • With a labio-lingual motion, contour the proximal aspect of the restoration in order to minimize flash and create a physiologic gingival embrasure. • Dry the restoration with a gentle stream of air. • Carefully check for defects such as voids, marginal defects, and excess material. • Clinically, additional composite can be added to the restoration, as needed providing the rubber dam has maintained moisture control. • The final polish of the restoration is accomplished using snap-on-polishing discs (Ex, Soflex) in a slow speed hand piece. Starting with the medium, and progressing to the fine and extra-fine grit, gently polishes all aspects of the composite restoration. • Figure 7.35 shows some of the instruments for composite resin polishing.

a

b Fig-7.35 A (a) Polishing strips, (b) finishing diamond burs.

Fig-7.25 B Finishing diamond burs for composites

(for remove composite excess.

Fig-7.35 C Polishing strips and polishing discs for composites.

Fig-7.35 D Sof-Lex dicks and the snap-on mandrel and Moore-Flex Dicks.

Fig-7.35 E Brasseler polishing cup and points and Min-identoflex polishing cup and point with snap-on mandrel .

7.3 PRACTICAL CLASS FOR CLASS III COMPOSITE RESTORATION. 1. Class III restoration on tooth 12 (mesial). 2. Class III restoration on tooth 33 (distal).

PRACTICAL SESSION 1. INSTRUCTION :

Class III composite resin on 12 (Mesial)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling -underfilled / overfilled -overhanging or deficient margin -preserve anatomy -maintain contact point Polishing -smooth and shiny

PRACTICAL SESSION 1. INSTRUCTION:

Class III composite on 33 (Distal)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling -underfilled / overfilled -overhanging or deficient margin -preserve anatomy -maintain contact point Polishing -smooth and shiny

7.4Tooth preparation for class III in clinical procedure. The tooth is prepared with dental handpieces and assorted burs. Once the tooth is prepared, it is restored with composite. Equipment and supplies (Fig-7.36 to Fig-7.37). Basic setup: • Mouth mirror, explorer, cotton pliers. • Air-water syringe tip, HVE tip, and saliva ejector. • Cotton rolls, gauze sponges, cotton pellets, cotton tip applicators, and dental floss. • Topical and local anesthetic setup. • Rubber dam setup. • High- and low-handpieces.

• • • • • • • • • • • • • • • • •

Assortment dental burs (including diamond and cutting burs). Spoon excavators. Hand cutting instruments (biangle chisel and wedelstaedt chisel). Base and liner with maxing materials and placement instruments. Etching and applicator, if necessary (usually come with composite system). Primer ((usually come with composite system). Composite materials including a shade guide. Composite placement instrument (plastic instrument). Curing light with protective shield. Celluloide matrix strip and wedges. Locking pliers or hemostat. Finishing burs or diamonds #12 scalpels. Abrasive strips. Polishing discs. Lubricant Articulating paper and forceps.

Procedure Steps. • The patient is seated and prepared for the procedure. Confirm the procedure and review the medical history. • Rinse the patient mouth and apply the topical anesthetic and give LA. • The shade is determined for the composite materials. • Place the rubber dam. • Prepare the cavity. • Placed the base or liner. • Place the acid-etch for 15 second according to manufacture direction. • Place the matrix strip and plastic wedge. • Place the bonding material and light cure (10 sec) according to manufacturer direction. • Place the composite into the cavity and light cure (20-30 sec) according to manufacturer direction, if the material is self-cure mixed and place the cavity wait for a few minutes to set. • Remove the matrix strip and wedge. • Use the low-speed handpiece with finishing burs, diamond, and abrasive discs to finish the restoration. • Removed the rubber dam carefully. • Check the occlusion with the articulating paper, if any high mark removes it. • The patient mouth is rinsed and the patient is given postoperative instructions.

Fig-7.36 Composite tray setup. metal clip.

Fig-7.37 Celluloid matrix strip with

7.5 Class IV composite restoration. 7.5.1 ARMAMENTARIUM 7.5.2 CLASS IV CAVITY The cavity is represented by an axial wall that is the line of fracture (Fig-7.38). For this procedure, contact with the adjacent tooth is broken. Clinically, however, contact with the adjacent tooth may be maintained

in

order to conserve tooth structure. Extension of the outline form beyond the fracture site is minimized unless weakened or unsupported tooth structure is present. The fracture involves a triangular- shaped area of dentin surrounded by enamel that is beveled at a 45 degree angle, about 1 mm wide. No undercut or pin is necessary for mechanical retention as the composite restoration is retained by acid etching the enamel. Fig-7.38 Class IV line of

fracture. 7.5.2.1

FEATURES OF THE RESTORATION

The restoration restores all missing tooth structure including incisal edge, interproximal contact, and contours (Fig-7 .39 ). It extends 1 to 2 mm beyond the cavosurface bevel. The restoration terminates on an area of enamel that has been previously etched and painted with unfilled resin/bonding.

extent of

the

Fig-7.39 Extent of restoration. (A= extent of prepared cavity, B= extent of composite resin, C=

enamel)

unfilled resin,

D= extent of etched

7.5.2.2 MESIO-INCISAL EDGE FRACTURE STIMULATION 1. In order to stimulate a defect requiring a class IV composite resin restoration, a mesio-incisal fracture is created on maxillary central incisor. 2. The simulated fracture should involve a triangular-shaped area of enamel that is just into dentine. 3. The size of simulated fracture, depending upon the tooth selected, may increase in order to allow exposure of dentine on the fractures surface for purpose of this procedure. Clinically, however the preparation of dentine should be minimized. 4. Pencil the fracture line on the labial and lingual surface on the tooth selected. 5. The area of tooth structure to be removed and should extend approximately 3 mm gingivally and 3 mm distally from the original mesio-incisal corner. 6. The fracture line should extend gingivally to contact area, so that the restoration restores the contact as well as the missing mesio-incisal corner. 7. Using a tapered diamond bur in the high-speed hand piece, remove the mesioincisal corner of the tooth as described above. 8. a class IV composite resin restoration is retained mainly via acid etched enamel. 9. Therefore, establishment of retention with mechanical undercuts and threaded pins is not necessary in a small and moderate-size cavity. 10. With a diamond bur or carbide-finishing bur, create 45-degree bevel 1 mm wide along the entire cavosurface margin (Fig-7.40). 11. The bevel is located entirely in enamel and should not extend into dentine. Its purpose is to; a. Increase the tooth structure area for acid etching.

b. c.

Provide a suitable area for unfilled resin tag penetration. Remove unsupported enamel.

12. Clinically, the bevel has the effect of; a. Increasing the retention of the restoration. b. Decreasing the marginal leakage. c. Minimizing an abrupt visual change from the restorative material to the remaining enamel surface. Fig-7.40 Bevel cavosurface margin. r 7.5.2.3 CLEANING THE TOOTH 1. Using a rubber cup in slow-speed hand piece, clean the enamel surface with slurry of flour of pumice and water mixed in a dappen dish. Clinically, this has the effect of removing bacterial plaque and salivary contaminants, and cutting debris and stain from the prepared cavosurface bevel and adjacent enamel. 2. This procedure provides a clean surface that is more receptive to acid etching ( Fig-7.41). 3. Do not use paste-containing fluoride, as this will diminish the effect of acid etching. 4. Rinse the tooth with a water spray to remove the pumice. 5. Carefully dry the tooth with a gentle steam of air (do not over dry / desiccate the dentin). Fig-7.41 Clean the enamel. 7.5.2.4

LINING / BASE APPLICATION

1. Prior to acid etching, moderate and deeply exposed dentine must be covered to protect the pulp tissue from; a. The etching solution b. The chemical irritation of the composite resin. 2. When a great amount of tooth structure has been lost due to caries or fracture, a base should be used underneath the restoration. Otherwise, lining the exposed dentine should be sufficient in protecting the pulp. 3. Materials for use as lining or base for tooth colored restoration has been described in “Pulp Protection”. 4. if the cavity is very deep and very close to the pulp (that requires indirect pulp capping) or small, pin-point pulp exposure occur while doing cavity preparation (that requires treatment with direct pulp capping), then ,calcium hydroxide lining (e.g. Dycal) need to applied on the tooth surface overlying the pulp. 5. dispense a drop each of the catalyst and base pastes of the calcium hydroxide material onto a paper-mixing pad (Fig-7.42)

Fig-7.42 Mixing calcium hydroxide 6. Using the mixing instrument provided with the material, mix the catalyst and base together. 7. Touch the tip of the mixing instrument to the paste and carry a small amount

to the dentine to be covered. 8. Touching the instrument to the dentine will transfer the calcium hydroxide to it. 9. Apply to form a thin, uniform layer and allow the material to set. 10. Always remember that when calcium hydroxide lining is placed overlying the pulp / close to the pulp, placement of a base above the calcium hydroxide layer is needed (using either conventional GIC such as Fuji IX or RM-GIC such as Fuji II LC) before restoring the cavity with composite resin. This is to protect the calcium hydroxide layer from fracture as they become rigid after set. 11. Inspect the preparation to ensure dentine overlying the pulp has been covered with the calcium hydroxide. If not, repeat the previous mixing steps. 12. Lining / base should not extend beyond the DEJ onto enamel, as it will inhibit acid etching and subsequent bonding. 13. Excess lining / base is removed with an explorer or spoon excavator.

7.5.2.5

ACID-ETCH TECHNIQUE

1. Dispense two to three drops of phosphoric acid solution (35% to 37% depending on manufacturer’s formulation) into a plastic well or dappen dish. 2. Using a small brush or applicator, paint the enamel with the acid gently for 20-30 seconds (follow the manufacturer’s instruction). 3. Then, return the brush to the dispensed acid, in order to wet the enamel with fresh etchant (Fig-7.43). 4. Be certain to coat the prepared enamel bevel as well as 4 to 5 mm of intact adjacent surface enamel. 5. Following the acid application, rinse the tooth thoroughly from all aspects with a water spray for 30 seconds (Fig-7.44). 6. With the air spray, dry the tooth carefully from all aspects to remove all moisture. The presence of any moisture on the enamel will interfere with the successful bonding of the resin. The etched enamel surface should exhibit a chalky white appearance.

with water. 7.5.2.6

Fig-7.43 Etching

Fig-7.44 Rinse

MATRICING

1. Place a 1 – ½ inch length of mylar matrix strip interproximally between the prepared tooth and the adjacent tooth. The matrix strip should extend gingival to the cavosurface bevel interproximally. 2. Place a transparent wedge from the labial to secure the gingival portion of the matrix strip against to tooth being restored (Fig-7.45). 3. Evaluate the position of the matrix strip and its ability to: Minimize the gingival extent of the composite. Simulate the contour of the ultimate restoration. Extend beyond the incisal edge in order to encompass the mesio-incisal edge being restored. 4. Clinically, a celluloid crown from is often used as an alternate from of matricing. 5. The crown from must be contoured to the approximate shape of the final restoration. It serves to delineate both the interproximal, palatal, and labial contours.

6. Test the final position of the Mylar matrix by practicing young direction of pull, which will be used in the following procedure. Fig-7.45 Matrix strip placement. 7.5.2.7 PLACEMENT OF UNFILLED RESIN / BONDING Applying one drop of the unfilled resin into a plastic well (is also known to as intermediary resin, bonding agent and enamel bond). Mix the two drops together with a fresh applicator brush (fig-7.46) and paint the unfilled resin over the etched enamel and protected dentine. Be sure to paint the unfilled resin beyond the fracture line over the etched enamel surface (Fig-7.47). The resin ensures wetting of and penetration into the etched enamel surface. This enhances retention and sealing of the composite resin. The unfilled resin is then light cured for 10 seconds. Fig-7.46 Mix bonding agent. on etched surface. 7.5.2.8

Fig-7.47 Paint

COMPOSITE MATERIALS

Composite resin restorations can be done with micro filled, marco filled, or hybrid materials. The micro filled materials should be used to restore incisal fractures only when the maxillomandibular relationship is normal and when the remaining natural teeth can serve as the primary support for centric, protrusive, and protrusive lateral functions. When the occlusion is heavy and the incisal composite restoration is expected to bear most of the occlusal load, macrofilled or hybrid type of composite material are specifically indicated because of their greater fracture resistance in stress-bearing situations The best materials for restoration of incisal fracture are as follows: 1. Highly polishable hybrids: Prisma APH; Herculite XRV; Z-100. 2. Heavy filled micro filled composite materials: Heliomolar, Helio Progress. 3. Semipolishable hybrids: Silux plus, durafil VS. 4. Some brand of composite materials set (Fig-7.48).

( A)

7.5.2.9

( B)

Fig-7.48 Composite resin materials set.

COMPOSITE RESIN PLACEMENT

Using a plastic instrument, insert the composite resin into the preparation taking care to avoid creating pockets of air or voids in the restoration. The resin should be introduced into the cavity incrementally, with each layer less than 2 mm in thickness. This is to ensure good depth of cure and to reduce the polymerization shrinkage of the composite resin. Remember to stabilize the matrix strip across the palatal aspect of the cavity preparation with finger pressure during insertion of material. Once the cavity has been filled, the matrix must be drawn across the preparation in order to simulate the ultimate contours of the restoration. Light cure the composite on the labial and lingual surface for 40 seconds

each. Held the matrix firmly onto the tooth surface for a few minutes while the composite is being cured or polymerized. Proper positioning of the strip will minimize the amount of finishing while ensuring good adaptation of the material to the cavity preparation. Repeat the previous steps until the cavity is slightly overfilled with the composite resin. When using a chemical cure composite resin, place an equal proportion of base and catalyst pastes of the composite resin on the paper pad. Mix the paste thoroughly for 30 seconds with a plastic mixing spatula. Condense the freshly mixed composite resin into the disposable tip of a composite injection syringe. Seal the tip with a plug provided and place the tip into the syringe. Complete the loading of the syringe quickly so as not to encroach on the working time of composite resin. The mix can then be injected into the preparation (Fig-7.49, 7.50). Fig-7.49 Material placement. Positioning the strip.

Fig-7.50

7.5.2.10CONTOURING, FINISHING, AND POLISHING Remove the transparent wedge and the Mylar strip. If gross marginal excess of material present, begin shaping the contours of the ultimate restoration using a diamond bur in the high-speed hand piece (Fig7.51). Some of the burs that can be used are diamond bur L10 for contouring the labial surface and pear shape or F40 bur for contouring the palatal surface and cingulum area. The composite resin should extend beyond the limits of the cavosurface bevel for purposes of esthetics, sealing and retention. Sand paper disks in a slow-speed hand piece may be used on the labial and incisal aspects to further contour the restoration (Fig-7.52). White stone (tapered and round shape) can also be used to further contour the labial and palatal surface of the restorations. The proximal surface can be contoured using an interproximal finishing strip that has two abrasive surfaces (Fig-7.53). Pass the strip through the contact from the incisal aspect. With a labio-lingual motion, contour the mesial aspect of the restoration in order to minimize flash and create a physiologic gingival embrasure (Fig-7.54). Dry the restoration with a gentle stream of air. Carefully check for defects such as voids, marginal defects, and excess material. Clinically, additional composite can be added to the restoration, as needed providing the rubber dam has maintained moisture control. The final polish of the restoration is accomplished using snap-on-polishing discs (Ex. Soflex) in a slow speed hand piece. Starting with the medium, and progressing to the fine and extra-fine grit, gently polishes all aspects of the composite restoration. Clinically, the rubber dam may be removed at the completion of finishing so that the restoration first can be checked in centric occlusion and protrusive guidance and then polished additionally. Fig-7.51 Remove excess labial.

Fig-7.52 Contour

Fig-7.53 Contour lingual. proximal surface.

7.6

Practical Class Class IV Composite resin on 11 (MI) Class IV Composite resin on 12 (DI)

PRACTICAL SESSION 1. INSTRUCTION:

Class IV composite resin on 11(MI)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet

Fig-7.54 Contour

Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling -underfilled / overfilled -overhanging or deficient margin -preserve anatomy -maintain contact point Polishing -smooth and shiny

PRACTICAL SESSION 1. INSTRUCTION:

Class IV composite resin on 12 (DI)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling -underfilled / overfilled -overhanging or deficient margin

-preserve anatomy -maintain contact point Polishing -smooth and shiny

7.7

Class V composite restoration.

7.7.1 ARMAMENTARIUM Basic tray setup: 1. 2. 3. 4.

Mouth mirror Explorer Tweezers. Periodontal probe. Cavity preparation:

1. 2.

Contra angle slow speed hand piece Burs. Mixing and placement:

1. 2. 3. 4. 5.

Mixing pad. Mixing spatula. Glass ionomer. Cavity conditioner. Plastic instrument (Teflon- type) instrument. Finishing:

1. 2. 3.

Diamond finishing bur White stone points Snap on soflex discs points.

7.7.2 CLASS V CAVITY Class V cavity preparation, by definition, are located in the gingival one third of the facial and lingual tooth surfaces. Because of the esthetic consideration, composite resin or GIC (Fig-7.55A) used for the restoration of class V lesions. In certain circumstances, GIC and composite (Fig-7.55B) resin restoration are used together in the same cavity (using different layers of material), to obtain good adhesive of GIC to dentine and achieve greater aesthetic and strength of composite resin. This type of technique and restoration is known as “sandwich technique” and “sandwich restoration”. (A)

(B) Fig-7.55 (A) GIC Light cure, (B) Composite self sure.

7.7.2.1 OUTLINE FORM The outline form of the cavity stops at the extent of the defect or caries, and removal of tooth structure can be kept to a minimum. However, unsupported enamel should not be left in area subject to high load. For the restoration of the cervical abrasion lesions, for which glass ionomer cement is often used, the outline from of the defect is used as cavity outline from but sometime the coronal (enamel) margin is altered (Fig-7.56 to 7.59). The cavity margin should ideally be placed above the gingival margin to gain better moisture control. Fig-7.56 Class V cavity. with two pin holes

Fig-7.57 Large class V cavity

Fig-7.58 Class V cavity in premolar.

Fig-7.59 Cavity outline.

7.7.2.2

RETENTION FORM

A particular retention from does not need to be consciously provided, in fact, if one is too much of a box form, air bubbles will be trapped in the corners. In order to increase adhesiveness with the cement, a fresh dentine surface is exposed as much as possible and any carious dentine is removed.

7.7.2.3

PREPARATION FOR CONVENTIONAL CLASS V CAVITY

The conventional class V for composite is indicated for portion of a carious lesion entirely or partially on the buccal / labial or lingual root surface of the tooth. The preparation will be limited only to removal of any defects and conserving as much tooth as possible. The features of the preparation include a 90-degree cavosurface angle, uniform depth of the axial line angle and sometimes, the retentive groove. Enter the tooth using a tapered TC or similar shaped diamond bur at a 45degree angle to the tooth surface by tilting the hand piece distally. As the cutting progress distally, maintain the bur’s long axis perpendicular to the external tooth surface during preparation of the outline form. This should result in 90-degree cavosurface margins. The depth of the cavity (axial wall depth) is about 0.75 mm. this depth will provide adequate external wall width for: Strength of preparation wall

Strength of composite Placement of retentive groove, if necessary. The axial wall should follow the original contour of the root surface i.e. convex outward mesiodistally and sometimes occlusogingivally. Final tooth preparation consists of the following steps: 1. Removing remaining infected dentine on the axial wall or old restoration (if applicable). 2. 2.Lining, if necessary 3. Sometimes, may need to prepare retentive groove. However, retention groove is considered unnecessary when axial depth into dentine is only 0.2 mm and the periphery of tooth of the tooth preparation is still in enamel. No .1/4 round bur is used to prepare the groove, along the full length of gingivoaxial and incisoaxial (occlusoaxial) line angles. These grooves are about 0.25 mm in depth into the external walls. Beveling of the enamel margin is sometimes done and is indicated in the case of : 1. The replacement of an existing, defective class V restoration, which not previously beveled. 2. For a large, new caries lesion. The advantages of the beveled preparation are: 1. Increase retention due to the greater surface area of etched enamel. 2. Decrease micro leakage due to the enhanced bond between the composite and the tooth. 3. Decrease the need for groove retention (therefore, less removal of tooth structure).

A.CLEANING AND CAVITY CONDITIONER The cavity preparation is rinsed with water and lightly air-dried. Condition the cavity to cleanse the preparation, which removes the smear layer and makes the adhesion of the cement to the dentine surface more reliable. B.PLACEMENT RESTORATION. It is necessary to remove excessive moisture from tooth structure. Mixed glass ionomer cement as soon as possible in order to obtain the best bond.

The restorative glass ionomer cement is placed in the cavity using a syringe or a special instrument for pacing and contouring GIC. A cervical matrix can also be used to contour the restoration along the margins while the restoration is setting. The basic anatomy is finished while the cement is in the fluid state. C.CONTOURING. If fluidity disappears while the anatomy is being carved, do not try to create any more anatomy, keep your hands off. Attempts to change the contour after fluidity disappears causes stippling or bumps on the surface. If there is a lack of material, another mix is made quickly and an additional layer added.

D. FINISHING. The finishing should be done at least one day after the placement of the restoration to allow surface hardness to occur. One technique is to contour the basic anatomy using a diamond point for finishing, and then to finish the surface with snap on discs or something similar. Abrasive strip is used to contour the proximal surfaces. Because the GIC is now stable in water, white stone points and silicone points can be used with adequate irrigation to contour the restoration. Finishing with polishing pastes, brushes, and rubber cups should be avoided because the heat produced may cause craze lines.

7.7.2.4. FEATURES OF CAVITY CLASS V ON CANINE TOOTH. (A) (B) Fig-7.60 (A) Class V

preparation with composite, (B) Step by step preparation.

Fig-7.61Class V caries and outline form. 45-degree.

preparation.

7.7

Fig-7.62 Bur held at

Fig-7.63 Completed large, beveled conventional class V

Practical class. Class V GIC on 25 (B) Class V Composite on 11 (B) Class V GIC on 33 (B)

PRACTICAL SESSION 1. INSTRUCTION:

Class V GIC on 25 (B)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary Filling -underfilled / overfilled -surface smoothness -overhanging or deficient margin -preserve anatomy Polishing -smooth and shiny

PRACTICAL SESSION 1. INSTRUCTION:

Class V Composite on 11 (B)

Date:…………………….

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary

Filling -under filled / overfilled -surface smoothness -overhanging or deficient margin -preserve anatomy

Polishing -smooth and shiny

PRACTICAL SESSION 1. INSTRUCTION: Date:…………………….

Class V GIC on 33 (B)

ACTIVITY LECTURER’S NAME AND SIGNATURE COMMENTS Cavity Preparation -conservation of tooth structure -outline form -resistance form -retention form -convenience form -cavity toilet Base / lining -understand the indication -materials used -sufficient thickness -uniform layer -confine to area that is necessasary

Filling -under filled / overfilled -surface smoothness -overhanging or deficient margin -preserve anatomy

Polishing -smooth and shiny

EVALUATION CRITERIA EVALUATION CRITERIA GRADE Excellent A student is able to complete the task without any assistance and direct guidance from the supervisors and has excellent knowledge about the procedures. 4 Good A student need a minimal amount of help to complete the task and is able to show evidence of understanding of the concept / procedure. 3 Satisfactory A student need to be repetitively guided to complete the task and need further explanation about the given concept / procedure. 2 Poor There has been irretrievable damage to the tooth structure and the student lacks the knowledge of the given concept / procedure. The supervisor has to complete the stage of treatment for the student. 1

Assessment sheet for hands skill exercises (1) EXTERNAL OUTLINE FORM(inc bevel) Exercise Marks Signature Marks Signature Exercise1 Shape 1 Exercise 2 Shape 2 Exercise 3 Shape 3 Exercise 4 Shape 4 (2)

REPEAT

INTERNAL FORM (Parallel walls / undercut, internal line angle)

Exercise Exercise1 Shape 1 Exercise 2 Shape 2 Exercise 3 Shape 3 Exercise 4 Shape 4

Marks Signature

Marks Signature

(3) FINISH ( SMOOTHNESS) Exercise Marks Signature Exercise1 Shape 1 Exercise 2 Shape 2 Exercise 3 Shape 3 Exercise 4 Shape 4

REPEAT Marks Signature

REPEAT

Reference: • Pickard HM, 1970 A Manual of Operative Dentistry, 3rd. ed, Oxford University Press. • Robinson DS, Bird DL, 2007 Essentials of Dental Assisting, 4th. ed, Saunders. • Pickard HM, Kidd EAM, Smith BGN, and Watson TF, 2006 Pickard”s Manual of Operative Dentistry,8th. ed , Oxford University Press. • Gopinath VK, Sam’an MI, Noorliza L, Rashid I, and Zaripah B, 2007 Manual for Opreative Dentistry :P2Y2, USM. • Phinney DJ, and Halstead JH, 2000 Delmar’s Dental Assisting. A comprehensive Approach, Delmar Thomson Learning. • Sikri VK, 2006 Text book of Operative Dentistry, CBS. • Roberson TM, Heymann HO, and Swift EJ, 2006 Sturdevant’s Art and Science of Operative Dentistry, 5th.ed, Mosby. • Summit JB, Robbins JW, Hilton TJ, and Schwartz RS, 2006 Fundamentals of Operative Dentistry; A contemporary Approach, 3rd.ed, Quintessence. • Kantorowiczs GF, 1979 Inlays, Crowns and Bridges. A clinical Hand

Book,3rd.ed,Wright.