Detection of a second mesiobuccal canal in the mesiobuccal roots of maxillary first molar teeth.
OBJECTIVE: The aim of the present study was to determine whether the MB2 canal in the mesiobuccal root (MBR) of maxillary first molars could be identified through a clinical access cavity preparation, with and without magnification. STUDY DESIGN: One hundred extracted maxillary first molar teeth were collected. After a clinical access cavity preparation with careful use of bur to locate any additional canal (dentine troughing), the MB2 canals were located in 2 stages. Stage I was located with unaided vision and stage II was located under moderate magnification with x3.5 magnifying dental loupes. All specimens were stained, rendered transparent, and then classified. The number of canals detected by stage was analyzed statistically by a chi-square test. Statistical significance was considered to be P < or = .05. RESULTS: Under magnification, the number of detected MB2 canals was increased from 55 (56.7%) to 61 (62.9%) teeth. Cleared teeth showed 77.32% of MB2 canals. The effectiveness of MB2 location was 73.3% and 82.7% in stage I and stage II, respectively. There was no statistically significant difference between the 2 methods of detecting the MB2 canal (P = .3). CONCLUSIONS: The use of magnification enhanced the ability to detect the MB2 canals, although the difference was not statistically significant. The MB2 canals could not be detected in 16.5% of the teeth, mainly because of pulpal calcification.