Procedural errors in endodontics
extra notes
slide 3 :
misdiagnosis : the tooth don't need endo treatment (wrong diagnosis).
inattention : right diagnosis but wrong treatment ( ex:  lower left 5 has irreversible pulpits but you do RCT for the lower right 5 )
slide 4 :
MB2 is always there (94%) , you just have to look for it.
if the tooth is vital then it's a problem .
distal root of mandibular molar : its the difficult tooth to treat.
in lower anteriors its very easy to miss the lingual canal , because the access is coming from the lingual so extend your access to look for the canals.
access cavity should be large enough to see the work and small enough not to compromise the tooth structure.
3rd canal in upper premolars : 2 buccal and 1 palatal
slide 6 :
this pt. was at a high risk for  bisphosphonate relate osteonecrosis ,she developed an abscess in lower right area , her dentist managed to do RCT for lower right 7 and couldn't find any canals in 6 .
CBCT gives you all the details :
- 6 : hypercementosis and the 4 canals are missed in it .
- 7 : the distal root has 2 canals that joined together , only MB is treated and ML is missed.
slide 8:
why endo treated teeth fractured more often ?
1) because of the loss of hydration (necrotic teeth or endo treated has loss of hydration).
2) remaining tooth structure (how much dentin is left).
there is a study that compares the stiffness of certain type of teeth , the 1st group just did access cavity on molars occlusally and compared them with virgin tooth (2ND GROUP); the stiffness was reduced by 5 % . 3RD GROUP they did a deep cavity and the stiffness was reduced by 60 %.
access cavity by itself is not a major factor but usually endo treated teeth have already lost a significant tooth structure.
another factor , loss of proprioceptions for endo treated teeth so nth to stop you from biting too hard.
if they fracture or you know they are more susceptible to fracture you need to relieve the occlusion and provide cusp protection.
slide 9 :
every thing we do in endodontic is control the infection.
slide 16 :
time : most important factor, perforation that happens just now is not as bad as the one happens before years.
size :the bigger perforation , the bigger the problem is.
location : if its at the crestal bone level , its the worst type. the pt. will end up with apical migration of junctional epithelium and formation of  pseudo-pocket.
slide 18 :
apex locators : if they touch the PDL they will give zero reading so if you suspect a perforation use apex locator.
slide 19 :
non surgical treatment : disinfect the canals then seal the perforation.
if the perforation is more apically its more difficult to be treated non surgically.
furcation perforations are the easiest to treat.
slide 20 :
we can use the surgical treatment if the perforation site is accessible (like the buccal or labial site)  .
the more apical we go the more easier to do it surgically.
we do the disinfection non surgically but we provide the seal surgically.
intentional re-plantation : we extract the tooth the do RCT then splint it back .
slide 21 :
this case shows upper left canine which has cervical root resorption and it  perforates the pulp (it was not vital) ,treatment was provided by  surgical access and seal it by MTA then suture it.
slide 23 :
ledge is the most common
slide 25 :
not bad RCT but the symptoms persist so the photograph wasn't good and this is a good example OF TRANSPORTED CANAL.
slide 28 :
this debris mean that you didn't clean the canal properly and this debris contain bacteria so we wont get healing.
slide 29 :
in theory if we break a file inside the canal in an aseptic condition its not a problem.
the more you use the files the more you can get cyclic failure.
too much fatigue >> torsional failure and we reduce it by torque control  (for rotary).
most imp. factor is the preoperative status of the tooth ( vital or not)
other factors : stage (the record wasn't clear ) , if its beyond curvature , at the coronal or apical part , type of instruments (SS is the easier to remove).
slide  30:
retrieval is the 1st option (to take out the file) , you usually prepare until the final level by GG then by Masserann (pointed instrument , sorry the record wasn't clear ) put it around it and by a good grip pull it out.
if its not possible to retrieve it you can bypass it ( it s a conservative way but be sure not to break another one ).
slide 31 : example of file retrieval.
slide 32: example of bypassing the file
slide 34: you can see the gutta percha for sinus tract
slide 35 : example of apexectommy , here we cant leave the file because of the infection .
slide 36 :
copious irrigation ; mainly we used the irrigation to disinfect the canals , flush the debris and lubricate the instruments so don't work on dry canals.
preflaring the coronal canal : reduce the stress on the file.
achieve a glide path : when we work on rotary files don't put your rotary files until you reach size 20 manually.
single use of the instrument reduced the cyclic of fatigue.
in England any instrument enter the pulp you have to discard it because of mad cow disease that caused by a protein not by bacteria and its not killed by normal sterilization.
slide 39: 
over extension : to prepare the canal beyond the apical constriction.
if the tooth vital its not a big issue but if the tooth is infected it's a big issue.
slide 40 :
sodium hypochlorite burns every organic tissue but its still our choice because :
1) its effect on bacterial biofilm is unparalleled 
2)its the only one that dissolve the organic tissue.
slide 41 :
strict working length : if the WL was 21 mm put a bend on ur needle on  19 mm (don't use rubber stopper because it will move )
antibiotics : no strong evidence about it .
slide 42 :  if you want to dry the canals you either aspirate or use the paper point.
slide 49 : we tie the both ends on the bow
Good luck