Study of internal morphology of root-canal treated single-rooted mandibular second molars in a Greek population

Abstract

Background/Aim: To determine the prevalence of single-rooted mandibular second molars in a Greek population and examine their internal morphology with the aid of intraoral periapical radiography. Material and Methods: Clinical records of 531 root-canal treated permanent single-rooted mandibular second molars were collected from the Postgraduate Clinic of the Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Greece and from private dental clinics in the same city. The clinical records, along with the radiographic examination, were evaluated to determine the overall frequency of single-rooted mandibular second molars together with the number of root canals and their course. The root canals were categorized using Vertucci's classification with the addition of 3 further types where appropriate. Results: Out of 531 mandibular second molars; 102 (19.2%) presented a single root; 427 (80.4%) presented two roots; 2 (0.4%) presented three roots. In a total of 102 single-rooted mandibular second molars 31 (30.3%) presented with Type I, 18 (17.6%) with Type II, 14 (13.7%) with Type IV, 7 (7%) with 3 additional root canal types and 32 (31.4%) with a C-shaped root canal system. Conclusions: One out five mandibular second molars was single-rooted in a Greek population. The internal morphology of these teeth can be very complex with regard to the numbers and courses of root canals.