Perio Lec 4

‫ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ‬ Today we will talk about very important topic in dentistry and it should be totally understood and that’s it endo perio lesion or the relation ship between periodontics and endodontics . As we know we are dealing in perio with the outside of the tooth or the tooth root, however , the inside of the tooth is communicating with the outside of the tooth via 3 main avenues or passages and these include mainly 1)apical foramina (The most direct route of communication between pulp and periodontium) 2)accessory (lateral) canals 3) dentinal tubules. Therefore these open passages are 2 direction passages so there is anatomical variation , so fluid, bacteria, harmful products of bacteria can move from the pulp tissue to the periodontal area and vice versa , it also can go the other way around so when we are saying endo perio that its mean that the problem start in the pulp and spread outward to the periodontal area and that’s the upper drawing , the lower drawing the arrows coming from periodontal pocket and going into pulp tissue that s is perio endo lesion .

Differential diagnosis is so important, because we want to know where the problem have started , although the sequence is the same, so both perio, endo lesion can occur in the same tooth either together (simultaneously) or one may proceede the other, so they can present at the same time in this case we call it endo perio lesion. As we said the endo perio lesion can start as either endo lesion and move toward periodontal area or the other way around or it may be both just happening at the same time and then they merge together and become as one lesion and pathway of infection spread in case of endo perio lesion through 1) apical foramina 2)accessory canals and as you know in majority of single rooted tooth they are in apical third of root, but they more common in the molars in furcation areas .

3)Exposed dentinal tubules whether due to trauma , tooth brushing , caries , surgical procedures , or developmentally when cementum and enamel don’t meet at CEJ thus leaving areas of exposed dentin. 4)Cracks and fracture lines can communicate all the way through the root and to the pulp tissue 5) iatrogenic root perforation for example dentist trying to do root canal and perforate into

periodontal area and then bacteria may spread to pulpal tissues and periodontal area . Etiology: when case start in the pulp ,most likely due to 1) caries, caries will extend into pulp chamber , bacteria will go all the way there and from there they will go either through apical foramen, accessory canal , if you look to this tooth from the bottom , restorative procedures , traumatic injury , or tooth cracked due to trauma and then we end up with endo perio lesion.

If you look to this radiograph for example how do you know this lesion start as endo or perio lesion ? In the radiograph still we have a crest there ,but yet we have a good area of radiolucency .

Perforation , some thing extruding, or it may be accessory canal and there is extrusion of material to this canal and most likely its accessory canal .

2)Traumatic injury for example and he come with (‫)واﺣﺪ ﺑﻴﺎآﻞ ﻓﺮﻳﻜﺔ ﺑﻴﻄﻠﻌﻠﻮ ﺣﺠﺮ‬very sever pain the tooth may not be fractured but pulp affected from contusion so there may be reversible pulpitis , if we reversed the condition ,give to the patient anti inflammatory, it may come back to its normal form, but if we have pulpal injury and there is necrosis there are 2 possibillities : 1- no bacteria , no plaque , no infection so its unlikely to cause perio problem , pulp will be dead but without any other symptoms . 2- pulp is infected and there is a problem , endo bacteria , perio pathogens , we end up in inflammation , may lead to chronic inflammation or acute abscess , chronic inflammation may confined to apical area , or may spread to coronal part of periodontium , we know that infection try to follow the path of the least resistance especially if there is pus formation . if we have endo abscess where it will drain ? it can drain 1- through PDL space :we will see pus oozing from periodontal pocket . deep periodontal pocket depth , narrow deep pocket down to the apex , some times there is pus, we hold the probe and walk through , its normal depth, suddenely it will go down to the apex , this is a good indicator that its endo lesion , and we can confirm that by inserting gutta percha cone , take

radiograph , and we will see that cone will go all the way down . 2- it can drain through extraosseous fistulation and cortical bone , elevate periosteum and soft tissues and drain through sulcus or it may slide through the bone , perio probe cant penetrate into a pocket . upper left picture perio abscess , look how deep the probe goes , this true endo lesion with furcation involvement , we have crown but we don’t see prober endo filling and if you look to bone around tooth you can see density is not right, so that bone eaten away and the last RG after treatment and there is healing in the furcation area .

now what is the influence of PDL disease on the pulp

as we know plaque is the major external etiologic factor, so bacteria go through PDL area , then dentinal tubules or even accessory canals or apical foramina , then to the tooth , the tooth may be totally intact , no caries , still we may end up with pulp necrosis ,due to inflammation by PDL pathogens which enter through the canals and we know that dentinal tubules usually covered so they have to be exposed , but how? Either by iatrogenic factors , or breakage , when they exposed and there is no bacteria, reparative dentine try to take care of it . Pulp response to long standing periodontitis , the tooth just die slowly , however perio disease rarely leads to pulpal involvement , most endo perio lesion start from endo.

Clinical manifestations of endo perio lesion:

Notes 1-We check for the vitality by cold test not electrical , because fluid in necrotic pulp still conduct electricity, and patient may feel response but may be its not a true response and I don’t like term pulp is vital I like tooth is responsive , it may be delayed response , exaggerated response in pulpal pathology, some times tooth may be partially vital , if toy look to this malar its not proberly filled , some times remnants of pulp tissue in root will be vital (alive) and the tooth gave you response but does this mean this tooth is healthy ? no it does not 2- in the case of sinuses patient will not complain because there is no pressure.

3- discoloured crowns especially in cases of trauma , and pulp will have hemorage , blood enter into dentinal tubules and give this dark colour may be reddish,black,bluish.

If u cannot finish endodontic treatment completely at least stabilize the case, disinfect the canal ,put temporary dressing ,then u can go toward perio treatment, remember treatment plan and sequence of treatment . What the effect of periodontal treatment on the pulp ? When we do aggressive root planning ,some time ,we remove the cementum which will open the dentinal tubules .resulting in tooth sensitivity or infection even in some cases retrograde pulpitis : which mean bacteria coming through the dentinal tubules . When we do root conditioning with an acidic material , the pulp may get irritated so these r some of undesirable side effects of periodontal treatment. What is the other way around? What the effect of endo treatment on periodontium ?? Generally speaking , proper endo treatment will have favorable results, poor endo treatment will end up with problem .

1- Inadequate RCT filling or seal which means that some bacteria still there , and it will leak out and cause problem . 2-Mechanical irritant. 3- Chemical irritant sometimes material go out side the tooth and irritate surrounding area and I saw a case where the dentist was irrigating using sodium hypochlorite , and it went through the canal to the tissues and the body react with severe inflammation. 4- Root perforation : either by post crown or through instrument and u can tell the result of this perforation that we have this furcation involvement and widening and more inflammation around the mesial root.

Root perforation associate with formation of periodontal pockets especially in the coronal 1/3. That’s mean the higher the perforation the worst the result because that make communication possible with PDL pockets.

How to detect root perforation ??? 1- sudden pain( no LA) ,bleeding coronal to perforation area . 2- Radiographs. if the lesion is established we will have increase in the probing depth , suppuration, mobility , tender to percussion(TTP) . Now, this condition one of the most difficult to diagnose and it is not uncommon and this is what we call root fracture or vertical root fracture .the problem is they don’t show on the RG ,but we suspect it for example, even if the tooth has proper endo treatment ,and we go around ,suddenly we notice deep probing , and actually we can not tell for sure until we open flap see this bone destruction , it is not due PDL disease, it is due fracture. This crack communicate the bacteria all the way to the pulp and the pulp become reservoir of bacteria . the only treatment is extraction . For root perforation treatment we should start as early as possible(A.S.A.P)to prevent or reduce granulation tissue, we have many methods and actually that’s the responsibility of endodontist. Now, if we have multi-rooted tooth we can do resection, we remove the infected root and leave the rest , hemisection or extraction. We can detect that (vertical root fracture) only clinically, open flap ( healthy periodontium ,

normal bone height ,pain laterally ,pus ,deep probing depth on the crack area ). Diagnosis of vertical root fracture: ¤ Clinical manifestation: narrow deep probing . ¤ Radiographic manifestation widening of the PDL , horizontal fracture visible on RG , vertical fractures r not . ¤ Other diagnostic method is: 1- Dies , we use iodine that will show u a line a long the root surface . 2- Differential in biting on the buccal and the lingual cusps in multi-rooted tooth , but actually I borrow from the pediatric clinic the band seater(the child will bite on so it will go between teeth when we make space maintainer) .back to differential biting u wrap piece of gauze aroud the handle of the mirror ,then u start asking the patient to bite on one cusp at a time , not the whole tooth,if he feels pain on biting on one of these cusps this is an indication that there is vertical root fracture . 3- Fiber optic light : u can see the crack ,but be careful not to burn the patient because it produce intensive heat . 4- flap. Treatment : ¤ single-rooted tooth: take the tooth out. ¤ multi-rooted tooth: u may have hemisection, root resection or extraction .

Radiograph may deceive u ,upper RG look like PA lesion ,however , when u open a flap u find this tooth is vital or responsive ,but what happen this destroyed PDL area is overlapped the root, so its look like PA lesion .

Sometimes we do root canal treatment even in case of vital pulp and we call this (elective endo).to avoid something before it happened , rather than we end up with endo- perio lesion , we do RCT to prevent future problems. Now, if u put a mirror , and this is vital tooth ( no problem in apical area ) we have area of perio destruction .we take RG , when u look to RG u will see this part of the destruction and you think its PA lesion, due to superimposition

Done by: Rania AL Bsoul. Thanks Amal for help. THE END Correction for crowns and bridges lecture #5: Page 20 . Posterior MCCs features: That’s why we prepare functional cusp about 1.5 mm THE CORRECT is That’s why we prepare the non functional cusp about 1.5 mm.