Evaluation of root canal morphology of human primary mandibular second molars by using cone beam computed tomography

The aim of the present study was to investigate the root canal configurations of primary mandibular second molars (PMSMs) using Vertucci classification. Materials and Methods: The root canal types of 228 PMSMs (228 mesial and 228 distal roots) were evaluated. In addition, the relationship between external root morphology and Vertucci classification was investigated. The Chi-square test or Fisher Exact Chi-square test was used for the evaluations, and P < 0.05 was considered statistically significant for all tests. Results: The most commonly observed root canal type, which was observed in 228 roots (50%), was Type 4 followed by Type 8 (15.79%), Type 5 (14.47%), Type 1 (9.21%), and Type 3 (6.57%). In 150 mesial roots, the root canal Type 4 was observed whereas the same type was observed in 78 distal roots, and the difference was significant (P < 0.001). In flat roots (82.9%), the most frequently observed root canal type was Type 4 (50.8%) (P < 0.001).

Various root canal types were observed in both mesial and distal roots although Type 4 was the most commonly observed. Root canal types showed a consistent relationship with separated and conical root shapes whereas the flat roots showed different root canal types.