C shaped canals: Mandibular second molar

Everything has changed, about protocols for root canal treatment, except the anatomy. #Root_canal_anatomy is still the same, we are just exploring it more and more and modifying our protocols accordingly.

Initially dentists were taught, there is one canal in anterior teeth and two in premolars and then three in molars with some xyz exceptions ;). With time, we found more canals and then it became usual to get like MB2, a mid mesial, etc. Now we have shifted to lateral anatomy, scouting lateral canals & apical delta are now a norm. Complex world and complex root canal anatomy!

Mandibular second molars are known for exceptional root canal anatomy. C shaped canal anatomy is very common among those. Here is one case from start to end with C shaped canal anatomy. Hope you will enjoy.



28 years healthy male came to our clinic with pain in right lower back tooth. He had history of root canal treatment by a quack few days back only. Pain was persistent in nature. He went to previous dentist but every-time he gave him antibiotics and analgesics.




C/E: #GIC filled in tooth 47 with some secondary/ untreated decay visible. Tooth was tender on percussion. R/E: RCTed (?) 47 with some loose GP in canals. Tx plan: Re-RCT and full coverage restoration thereafter.





If you notice here, previous dentist has not done complete de-roofing of pulp chamber. A good and adequate access is first step to success. Its not wise to directly pick your hand files and start exploring canal after you notice an orifice or blood oozing from canal. First step is to clean pulp chamber.





Here I have done complete de-roofing of pulp chamber and view is completely different.








GP were so loose in the canals, these came out with the probe only.




#Bent_K_files are my favorite for such cases. K files are bend and used in #Envelope_of_motion. I do not recommend using H files as they can weaken the roots and may cause strip perforation.

To learn about envelope of motion technique you can watch the video:


Another good gadget to use here can be any of irrigant activation device like Endoactivator (Dentsply), PATS (by Dr Mandar Pimprikar) or by ultrasonic agitation. Here I used #MM_sonic_1500.




After complete shaping and cleaning, there was a small GP left in the canal adherent to canal wall. It was removed with Bent H files. Bent H files are good alternative to Microdebriders as H files are very economical.



This is the picture after complete shaping and cleaning. Clean canals with C shape anatomy can be noticed.








Cone fit x ray was shot but there was not good tug back even adjusting GP cones. So, I decided to obturate with MTA apical plug and then backfill with warm GP.







It is mandatory to shoot an X-ray after MTA apical plug because MTA sets very hard and it is not possible to do any alteration afterwards. If somehow MTA has not reached to the apex, indirect ultrasonics are quite helpful if used immediately.



This case is very old, completed in 2014. At that time it was a protocol to put wet cotton or wet paper point on to the MTA and leave for 24-72 hrs. MTA needs moisture during setting. Now we do not put wet cotton and complete the case in one visit as MTA can take moisture from apical end.



In next appointment, remaining canal Filled with warm GP.


If composites are planned as post op restoration, it is mandatory to clean the chamber nicely for better bonding of resins. Citric acid is quite useful for this purpose. However, now a days, many sandblasting devices are available and are best for this purpose.



First layer of composites is always colored. It will be very helpful if some day we have to re-treat the case. Here it is Permaflo purple by Ultradent.







There is no one recipe for performing endodontic procedure or any other treatment. We have to modify the protocols according to the patient and the tooth. Outcome should be favorable for our patient thinking about long term predictability. So, always take wise decision thinking patient as your family member.

Thank you for your valuable time. Your comments and suggestions are always welcome. Dr Neeraj Narang #MicroDentistryIndia

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