Prevalence of Unclassified Root Canal Configuration in Permanent Maxillary First Molar in Indian Population

Background: If a canal is left untreated, it is a foci of infection. Therefore, it is critical to know the usual configuration of the root canal along with the variations in root canal anatomy, in order to keep the cause of endodontic failure to a minimum. Aim: This study investigated the canal configuration in maxillary first permanent molar mesiobuccal root radiographically followed by histological evaluation in Indian population. Methods: Endodontic access preparation was performed on 100 human permanent maxillary I molars and all the canals were explored. The mesiobuccal root was separated and radiographed in mesiodistal and buccolingual direction. India ink dye was injected actively in the root canal of each sample. The root samples were prepared for histological viewing. The slides made were observed under light microscope and canal configurations were tabulated. Results: The radiographic interpretations by observers were correlated with histological findings and analyzed statistically (p value). The radiographic findings revealed a good inter observer agreement (Cohen kappa). On matching histological and radiographic interpretations, it revealed 69.2% Vertucci type I predominance. New unclassified canal configurations were also observed. Conclusion: To divulge three dimensional architecture of the root canal, application of alone conventional radiography is not enough.