Root and canal morphology of Burmese mandibular molars

Aim To study the root canal morphology of Burmese mandibular molars using a canal staining and tooth clearing technique. Methodology Mandibular molars (331) were collected from indigenous Burmese patients and designated: first (139), second (134), third (58) molars. Foll owing pulp tissue removal and staining of the canal systems with Indian ink , the teeth were decalcified and rendered clear with methyl salicylate. Und er magnification (x3), the following features were evaluated: (i) root numb er and morphology, (ii) number of canals per root, (iii) root canal configu ration (Vertucci's classification), (iv) number of apical foramina per root , (v) number and location of lateral canals and (vi) the presence of interc anal communications. Results Most of the mandibular molars had two separate roots (90%, in first molars, 58% in second molars, 53% in third molars) and three-rooted teeth were (10%) confined to first molars. C-shaped roots occurred in 22.4% of ma ndibular second molars and a further 14.9% had two fused roots. The majorit y (81-100%) of conical distal roots possessed a simple type I (single canal ) configuration. Whilst the canal system elf mesial roots was more complex: 52-85% contained two canals, of which type II (two orifices, one foramen) and type IV (two separate canals) were the most prevalent. A broad range of 6.5-70% had intercanal communications. Fused/single-rooted molars had a wi de variety of canal system types but intercanal communications were rare ex cept in C-shaped roots (33%) of second molars. The majority of roots of all molars contained one or two apical foramina (91-96%,) and the apical third had the highest prevalence of lateral canals. Conclusions There was a high prevalence of three-rooted mandibular first mo lars and C-shaped roots/canals in mandibular second molars from a Burmese p opulation. Conical roots tend to have simple canal systems, whilst flatter/ broader roots have more complex canal systems.