Validity of different methods for MB-2 canal location in permanent maxillary molars

ABSTRACT

The purpose of this study was to evaluate the effectiveness of naked eye examination and Dental-operating microscope [DOM] examination for the location of second mesiobuccal canal [MB-2] in extracted maxillary first and second molars, considering the sectioning of the tooth as gold standard for the location of MB-2. This was a cross-sectional comparative study. One hundred extracted permanent maxillary first and second molars [50 of each] were stored in 10% neutral formalin. Using high speed headpiece standard endodontic access cavities were prepared. Initially, the mesiobuccal, distobuccal and palatal canals were located. Subsequently, the location of MB-2 canal was attempted by examining the pulp chamber floor with naked eye using only an endodontic explorer and canal confirmed with 10# K-file. MB-2 canal orifice was either located or not located with this method. Teeth in which MB-2 canal was not located were further explored under DOM. Yet again MB-2 canal orifice was either located or not located. Finally the mesiobuccal roots of each tooth were sectioned. The sections were explored with endodontic explorer and 10# K file with the adjunctive use of DOM at a magnification of 12x to decide the real presence of MB-2 canal. 42% and 60% of MB-2 canals in maxillary first molar, 20% and 38% of MB-2 canals in maxillary second molar were detected with naked eye and with DOM examination respectively. While 66% and 42% of MB-2 canals were actually present in maxillary first and second molar respectively as confirmed by gold standard [sectioning of teeth]. It is concluded that DOM examination may be more effective for location of the MB-2 canal than naked eye examination