Second Mesiobuccal Canal Treatment in a Predoctoral Dental Clinic: A Retrospective Clinical Study.

The aim of this retrospective clinical study was to evaluate the location and treatment of second canals in mesiobuccal roots (MB2) of first and second maxillary molars in a predoctoral endodontic clinic by the graduating classes of 2008 to 2015. These results were compared to similar clinical studies. Included in the study were 368 root canal treatments performed by 310 third- and fourth-year dental students at one U.S. dental school. All cases were done under faculty supervision, and the students were instructed to use dental loupe magnification. Students' evaluation sheets were used to deteremine the total MB2 canals treated in first and second maxillary molars. The results showed that, overall, 72.55% of the teeth had an MB2 canal treated. The frequency was higher in first molars (75.91%) than in second molars (56.92%) (p<0.05). Third-year students were able to detect 39 MB2 canals in 57 maxillary molars (68.42%), while fourth-year students detected 228 MB2 canals in 311 teeth (73.31%) (p>0.05). Under proper supervision by experienced endodontists, these dental students were capable of treating MB2 canals in maxillary molars. The frequency of MB2 canals located and treated by dental students with the assistance of experienced professionals was higher in first than in second molars. No significant difference was found between third- and fourth-year students. The incidence of MB2 canals located and treated in this study was found to be similar to that in other clinical studies.