Pedo Lec #14

Pulp Therapy for the Young Permanent Dentition Today we're going to talk about Pulp therapy for the young permanent denon, for example: 6th-7th teeth that have just erupted in a young adolescent patient or young permanent teeth in an adult. There are three types of pulp therapy procedures: 1. Apexogenesis: is a vital pulp therapy procedure, apexogenesis refers to a continuation of formation of the apex of the root, the procedure results in normal physiological growth of the apex. 2. Apexification: is a non-vital pulp therapy procedure, where there is also a continuation of formation of the apex but the pulp is non-vital (not a normal physiologic procedure). 3. RCT.

The pulp in young permanent teeth where the apex is not complete (immature teeth) is very important, and that's for two reasons: for the completion of apical closure, and the formation of dentine, especially the radicular dentine which will give the root its thickness and its strength. So the pulp is necessary for dentine formation. And the loss of vitality in these young permanent teeth before root completion leaves thin, weak roots that are prone to fracture. Therefore vitality should be maintained when possible to allow completion of root development.

Apexogenesis Apexification

vital pulp therapy procedure non-vital pulp procedure

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Apexogenesis: is a vital pulp therapy procedure performed to encourage physiological development and the formation of the root's apex, where the aim is to promote root development and apical closure.

The goals are: 1. To sustain viable Hertwig's epithelium root sheaths (HERS); the

cells of these sheaths promote the continuation of formation of the root. So what we are trying to do in Apexogenesis is to keep these cells and conserve their vitality to allow a continuous development of root length so we can get a favourable crownroot ratio. 2. To maintain pulp vitality, allowing odontoblasts to lay dentine. So if you got a vital pulp that means your odontoblasts are working, they will be laying dentine and that will give us more thickness of the root and less chance of root fracture. 3. To promote root end closure for GP obturation, this is especially in cases of Apexification. 4. To generate a dentine bridge at site of pulpotomy; if we do a pulpotomy we need a dentine bridge to cover the wound.

Techniques: 1. Indirect pulp capping - As we said previously for primary teeth, you’ve got deep caries, with further excavation you might expose the pulp and have an immature apex present. - If the tooth is asymptomatic and they have NO abnormal RG changes such as: periodontal ligament widening, periapical radiolucency or root resorption; then you can do an indirect pulp capping procedure. - In cases of trauma with class 2 fracture and immature apex. Class 2 Fractures might involve both the enamel and the dentine, and maybe even the pulp. If the fracture didn’t involve the pulp then you

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can do an indirect pulp cap and this will enhance the formation of the root. BUT in cases that the pulp had been exposed which is in class 3 fracture trauma, where all the enamel, the dentine and the pulp are involved then you should do DIRECT pulp capping and that will also help preserve the vitality of the pulp in order for the root formation to continue. 2. Direct pulp capping this is mainly for traumatic pulp exposure, especially small ones and when the time interval since injury is short. You don’t want the patient to come in the next day. He should come within a few hours after the injury in the same day, that’s when you can do direct pulp capping procedure for a trauma case. In a carious pulp exposure you can do what we call partial

pulpotomy. So remember, in primary teeth when we have carious pulp exposure we don’t do any direct pulp capping, we go ahead and do our Pulpotomy. In the permanent teeth, we do Partial Pulpotomy In a regular pulpotomy which you have learned, you amputate (remove) the pulp up to the cervical edge (margin); which is an arbitrary land mark. Clinicians did not determine this land mark for a clear scientific reason, but they just remove the whole pulp in the pulp chamber because they know that MOs have reached the enamel, the dentine and then the pulp but they still don’t know where exactly are they in the pulp. They are probably up to 1/3rd of the pulp or they reached a bit deeper, clinicians are not actually sure. So in Primary teeth, because of their small size, MOs could be anywhere, so the whole pulp is removed. While in Permanent teeth, you can try to estimate where the pulp is; if you got a carious exposure with no radiographic signs, you can probably remove to a depth of 1-2mm of the pulp ssue beneath the 3

exposure or, in some cases, deeper to reach healthy pulp tissue. That's what we call partial pulpotomy. 3. If the coronal pulp is still inflamed and severely compromised, then you may go a bit further and do a cervical pulpotomy, just like what you do in primary teeth, removing the whole pulp tissue from the pulp chamber. So what characterizes the permanent teeth is that you can start with the conservative technique; doing partial pulpotomy OR you can do a cervical pulpotomy if you feel that the whole pulp is inflamed in the pulp chamber. In all these cases we are talking about a healthy radicular pulp. So in partial pulpotomy, you have: a larger pulp exposure resulting from immediate trauma OR treatment is initiated long after the initial trauma.




Indirect pulp capping (IPC) We talked about this before, the same as that outlined for primary teeth; the tooth might be reentered following a procedure to remove remaining caries. But some clinicians like to do it in one procedure; they remove all the carious dentine and the last layer (near the pulp) is left in place to avoid pulp exposure and they line it with vitrebond liner, GI and then a crown. Some clinicians like to do a step-wise excavation technique, which means half of the caries are removed and then GI is placed. They get the patient to come after another week or month, giving some time for the fluoride to act on the affected dentine (to remineralise) and on odontoblasts (to form reparative dentine) and then they go back, remove the GI and try to remove a little bit of the dentine. By this, pulp 4

exposure can be avoided. This technique may take 2 or 3 steps. The doctor likes to do it in 1 step and just get finished with it. So clinicians differ on whether this should be a single; preferred by Farooq in 2000, or a 2-stage procedure; preferred by Camp.

The Rationale: For a tooth that has a carious lesion near the pulp, place a biocompatible material over the layer of the remaining carious dentine to prevent pulp exposure and estimate pulp tissue healing repair.

Indications: Normal pulp or reversible pulpitis (you should estimate that by clinical and RG criteria).

Materials: We can use: Calcium Hydroxide, Zinc oxide Eugenol, GIC, Risen modified GI + final restoration. The best material based on clinical studies is to use vitrebond liner (RMGI). It has Fluoride, it's an adhesive type, it doesn’t get washed away like calcium hydroxide. Then you can place GI and stainless steel crown for posterior teeth or acid etched composite resin for anterior teeth. Success rate is from 74% - 99% of the cases. It differs. It depends on how much caries you’ve removed, the healing potential of the pulp, if the diagnosis was wrong, type of material and the sealing that you do.

The objectives:  Restorative materials seal dentine from oral environment.  Vitality of the tooth is preserved.  No post treatment signs or symptoms. You don’t want the patient to come complaining of pain, sensitivity or any swelling after the treatment.  No RG evidence of external or internal root resorption or pathologic changes.  Teeth with immature root Apexogenesis and continual root development; you should see a continual development of the root aFer 3-6 months.

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Direct pulp capping (DPC) It’s the application of medication or dressing to the exposed pulp in attempt to preserve vitality. So you are placing it directly to the pulp. When you’ve got a small exposure of pulp encountered during cavity preparation, hemorrhage should be controlled, you apply a cotton pellet dipped with saline, with light pressure for 1-2 minutes, and aFer you remove it the bleeding should stop, In this case, you’ve got a healthy pulp. after that capping the exposed pulp with a material like Calcium hydroxide or Mineral trioxide aggregate MTA is indicated, followed by placing a restoration that seals the tooth from microleakage.

Indications: 1. Permanent teeth with minimal exposure of the pulp upon caries

removal. 2. Mechanical exposure (iatrogenic). 3. Traumatic exposure. 4. In all cases, the pulp should be normal with no pathology.

Materials, either of each: 1. Calcium hydroxide. 2. MTA; Histological

evaluation showed less inflammation, hyperaemia and necrosis, thicker dentine bridge. 3. Dentine bonding agent; the same boning agent that we use for composite, used on the top of the pulp. Clinicians suggested that it's effective as a permanent seal against M.O and they say that it's successful. The doctor is not convinced about that. Why is calcium hydroxide the most successful direct pulp capping? How and why does it work?  It has a high pH, so it promotes dentine bridge formation.  It has antimicrobial properties, effective in treating contaminated exposure. ''The most important thing that you need is biocompatibility; it shouldn’t harm the pulp and the antibacterial properties''.

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Technique: Please refer to the 2nd slide on page 9:

1st Cover the pulp with MTA or Calcium hydroxide. 2nd Place a big layer of GIC. 3rd Restore the enamel with composite. When you are using Calcium hydroxide, it's better to use the non-setting type as a 1st layer and then the seHng type as a 2nd layer. Some clinicians like to use either the setting or the non-setting alone. The non-setting type is pure calcium hydroxide (nothing added to it) so it's better to be added directly on the pulp. On the top of that, if you place GI directly you will probably push the material down, because the pulp tissue is very soft. so it's more practical to put another layer of Calcium hydroxide because it's from the same type of material in order to make another seal. Then you can place the GI gently. By this way you will have more layers and you will protect the pulp in a much better way. Success rate is 13% reported aFer 10 years in retrospecve studies of pulp capping procedure done by students. But 82% reported over 21 month's period done by dentists.

The objectives: Are the same as indirect pulp capping:

   

Restorative materials seal dentine from oral environment. Vitality of tooth is preserved. No post treatment signs or symptoms. No RG evidence of external or internal root resorption or pathologic changes.  Teeth with immature root Apexogenesis and continue root development; you should see a continual development of the root aFer 3-6 months.

Pulpotomy When the pulp is exposed; both the infected and affected coronal pulp is amputated, and the remaining radicular tissue that is judged to be vital is to be left behind. 7

 One type of pulpotomy is partial pulpotomy (Cvek pulpotomy): Cvek; the person who invented the technique, described it as: The aseptic, surgical removal of exposed pulp and dentine surrounding the exposure to a depth of 1.5-2mm.

Cvek Indications: 1. Traumatic or carious pulp exposure. 2. Mature or immature root (it can be done also in adults). 3. The pulp should be normal or should have reversible pulpitis.

The aim: Is to remove superficial irreversible inflamed pulp tissue; the pulp that you are removing is what you judge to be irreversibly inflamed. You decide that a portion of the pulp seems to be irreversibly inflamed so you remove it, but the rest of the pulp that is normal or reversibly inflamed is remained. So you leave a clean surgical wound on the surface and then irrigate with normal saline. You'll try to achieve haemostasis by using cotton pellet in order to stop bleeding. After that, the pulp wound is covered with calcium hydroxide against non-bleeding pulp. If you placed calcium hydroxide on a bleeding pulp you'll get poor results. Be careful not to have a blood clot that will diminish chances for hard tissue formation.

Q: how can we differentiate between reversible and irreversible pulpitis? We should rely on clinical, radiographic criteria; when you're drilling into a tooth and removing the caries, you reach a point where the caries have exposed the pulp, you look at the pulp tissue, does it look healthy? If it has a carious exposure then most probably the adjacent 2mm are affected, so you'll remove these 2mm too. Evaluate all aspects of the pulp tissue; Is there any healthy bleeding? Does the hemorrhage stop when you're trying to stop it? What's the color of the blood?

Materials; either: 8

1. Calcium hydroxide – non-setting + hard setting type + vitrebond

(RMGI) + GIC filling + SSC/AECR. OR 2. MTA + vitrebond (The more the layers, the more the sealing) + GIC + SSC/AECR .

Cvek Technique: Please refer to the pictures in the 2nd slide page 13:

1st Cover Calcium hydroxide (non-setting + hard setting). 2nd place liner (vitrebond or GIC or both). 3RD Composite. OR 1st Cover the pulp with MTA. 2nd place a liner (GIC or vitrebond). 3rd Composite.

The objectives: Are the same as the direct and the indirect pulp capping:

   

Restorative materials seal dentine from oral environment. Vitality of tooth is preserved. No post treatment signs or symptoms. No RG evidence of external or internal root resorption or pathologic changes.  Teeth with immature root Apexogenesis and continue root development; you should see a continual development of the root aFer 3-6 months.

Success rate is very high; 96% on traumacally exposed teeth, 94% on carious exposed permanent molar.

Factors affecting success: 1. Avoid any incorporating dentine chips into the pulp; when you

reach the pulp, make sure that all caries have been removed from the cavity; after you cleaned it you can enter the pulp cavity. Your work must be neat. 2. Marginal seal; which means all these layers that we're putting on top of each other.

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 Cervical pulpotomy It's just like what was described in Formocresol pulpotomy; except that calcium hydroxide is the medicament of choice. After the removal of the 2mm, if the bleeding doesn’t stop, and the blood was dark in color; it means that we have irreversible pulpitis, at least in the coronal portion. So we remove the entire pulp chamber up to the cervical level. But we should notice if the radicular portion looks healthy and the bleeding stopped, then we probably reached a healthy point. This is what we call cervical pulpotomy. The medicaments are the same as what we talked about before.

Some authors recommend RCT later because a high incidence of calcification is expected. From the slides:

Re-entry following completion of root formation is controversial. Cervical pulpotomy Technique: Please refer to the picture in the 2nd slide page 15:

1st Calcium hydroxide or MTA. 2nd GIC or vitrebond. 3rd composite. The possibility of pulp necrosis, infection, pulp canal obliteration may prevent negotiation of canals later, especially if it's done on irreversibly inflamed pulp. Calcification is infrequent if pulpotomy procedure is meticulous; that means if you did the procedure right, you won't get poor results. There should be a clean removal of pulp tissue, use of sterile instruments, use of rubber dam, avoiding contamination with dentine chips and MOs (first remove the caries with a bur and when you enter the pulp, change the bur and use a new one ) and careful application of calcium hydroxide on non-bleeding pulp. The more you're sensitive with the technique the better the results will be. 10

The objectives: Are the same:

   

Restorative materials seal dentine from oral environment . Vitality of tooth is preserved. No post treatment signs or symptoms. No RG evidence of external or internal root resorption or pathologic changes.  Teeth with immature root Apexogenesis and continue root development; you should see a continual development of the root aFer 3-6 months.



Apexification: It's very similar to root canal treatment, except that you're doing it in a tooth with an open apex. It's a method of inducing a calcified barrier in the root with an open apex or continuing apical development of an incompletely formed root in teeth with necrotic pulp. It’s a non-vital pulp therapy technique.

The goals are: To stimulate and preserve formative activity of the granulation tissue cells in the apical part of root canal; if you have a necrotic pulp in the apical part you will probably have an abscess, but the Hertwig's epithelium root sheath cells have a potential to form dentine and cementum to close the apex. So your objective is to keep these cells. What actually happens is formation of callus; it's not a regular barrier, it's weak calcified dentine or cementum, but is still enough to form a hard tissue barrier to prevent the overextension of the root filling material in the periapical tissues.

The objectives:  Induce root end closure or apical barrier.  No post-treatment signs or symptoms.  No radiographic evidence of root resorption or pathologic changes.

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Indications: It's indicated for non-vital permanent teeth with incompletely formed roots. Example; avulsed tooth ( 

‫)ا‬, we do re-implantation and splint it. Then we proceed with apexification; because the root wouldn’t completely formed yet and the apex was open.

Techniques; either:

1. Calcium hydroxide technique: Apexification is done over multiple visits. We keep changing the calcium hydroxide material in the canal until apical closure happens. In the 1st visit: You get x-rays, you measure the working length, gain access, clean and shape, irrigate with sodium hypochlorite; just like what you do in root canal treatment. You place non-setting calcium hydroxide, place a clean cotton pellet, IRM and GIC and then you send the paent for at least 3 months. 'You can ask the paent to come aFer 2 weeks, just to make sure there is nothing wrong'. In the 2nd visit – after 3-6 months intervals: You get another x-ray, you check the calcium hydroxide in the canal, is it still there? Is it functioning? Then you can leave it. You don’t have to re-open the tooth again. But if it looks like it had become resorped (especially apically), then you have to re-open the tooth, clean it and add more calcium hydroxide. The intention is to have calcium hydroxide at the apical end. The level of calcium hydroxide decides where the apical closure should be; if you make a mistake and calcium hydroxide doesn’t reach the apical portion, then the apical closure will be at that point, which means it will be short. If you got an apical stop aFer 3-6 months or somemes a year, then you can fill it with gutta-percha and do a filling.

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2. MTA technique: ''Mineral Trioxide Aggregate'' has become the miracle material; you don’t need to wait for a year, you only do two visits; one or two weeks apart. In the 1st visit: You get x-rays, you measure the working length, gain access, clean and shape, irrigate with sodium hypochlorite, if the pulp really is infected you probably place calcium hydroxide for one week and then you get your patient and place MTA. Some cases there is no need to put calcium hydroxide, you just put MTA straight away and you place a moist cotton pellet; which will enhance the hardening of the MTA. In the next visit – after a few days: Obdurate with gutta-percha (Thermofill); lateral condensation technique is not preferred because it may press too hard apically.

This technique is widely practiced by endodontists:  It decreases time spend; if we have behavior or transport problems.  It has excellent results; it's biocompatible, it enhances root development, it sets hard and fast (new MTA sets hard in 15 minutes).

Apical closure:  Various types of apical closure have been reported after apexification; it's related to the level to which the filling material was placed within or beyond the apical foramen.  The calcified bridge formed following apexification is a porous structure.  It's difficult to determine if apical closure has occurred; for this reason we take an x-ray and try to see it radiographically, or we can try to feel it by a file or paper point. If there is resistance that means we have apical closure.

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Types of canal closure: 1. Apical closure with definite, minimal recession of the root canal, where you’ve got obliterated apex. This type is the best. 2. The obliterated apex which develops without changes in root canal space (it's still irregular, there is no dentine developing inside the canal). 3. Thin, calcific root canal bridge has developed, you can't see it by a radiograph, you can feel it only by instruments that encounter definite stop. 4. Calcific bridge which forms coronal to the apex that can be determined radiographically (it hasn’t formed at the right place).

Materials for apexification: 1. Calcium hydroxide (mostly) 2. MTA:  it produces apical hard tissue formation, cementum will form, bone will regenerate normally.  Potential for fractures of immature teeth with thin root is reduced.  You can do it in 1 or 2 visits that shorten treatment me.

Clinical outcomes:  Apexificaon requires an average of 1 year +/- 7 months.  Older children with narrow open apex take less time for apexification than younger children with wide open apex.  Teeth without periapical infection take less time than teeth with periapical infection.



RCT The dr. didn’t explain them; only copied them from the slides:

Definition: endodontic treatment to eliminate pulp and periapical inflammation. Indication: permanent with exposed, irreversible pulpitis or necrotic pulps, when the status of the tooth and the architecture of roots will permit appropriate restoration of the crown. Objectives: 14

 Evidence of successful filling, not over/under extended.  No adverse post-treatment signs/symptoms such as: prolonged sensitivity, pain or swelling.  Evidence of resolution of pre-treatment pathology.

Done By: Nadia Matani ‫    ب و  ت ا‬ .! "    ‫وا  ا ص‬

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