Estimation of the frequency of second mesiobuccal root canal in maxillary first permanent molar teeth in subjects visiting teaching dental hospitals of Peshawar.

Objectives: To determine the frequency of second mesiobuccal canal (MB2) in a sample of 223 extracted maxillary permanent 1st molars. Study Design: In-vitro Cross-sectional study. Setting: Department of Endodontic at Peshawar Dental Hospital. Period: June 2019-Nov 2019. Material & Methods: The samples were processed with application of the Clearing Technique which includes demineralization with nitric acid, dehydration with ethanol and clearing with methyl salicylate. The samples were classified according to Weine’s system of root canal classification. Results: Among the 223 samples, 30% were found to have Weine’s type1 root canal in the mesiobuccal root (second mesiobuccal canal absent). Second mesiobuccal canal was present in majority of the samples (70%) with Weines type2 (2-1) predominant with 23.32%, Weines type3 (2-2) present in 15.7% and Weines type 4 (1-2) present in 21% of the samples. 9% of the samples could not fit into Weines classification so they were placed in Vertuccis classification for root canal system type 6 (2-1-2). Conclusion: The present study concludes that the second mesiobuccal canal is more frequently found in maxillary permanent 1st molar teeth than our textbooks report, irrespective of quadrant and gender. Therefore, time should be given to evaluation of its anatomy by the clinician before starting the root canal treatment for the greater good of the community.