Root and canal morphology of Thai mandibular molars

TLDR

The study investigates the root and canal morphology of 351 mandibular permanent molars from an indigenous Thai population. Teeth were cleaned, pulps dissolved with sodium hypochlorite under ultrasonication, injected with Indian ink, rendered clear by demineralization and immersion in methyl salicylate, and examined for root and canal morphology. Among the molars examined, 13 % of first molars had a third disto‑lingual root, 10 % of second molars were C‑shaped (mostly type I or IV canals), and 68 % of third molars had two separate roots (61 % with two canals), with type I canals common in three‑rooted teeth, indicating Thai molars share features of both Caucasian and Chinese dentition.

Abstract

To investigate the root and canal morphology of 351 mandibular permanent molars collected from an indigenous Thai population.The cleaned teeth were accessed, the pulp dissolved by sodium hypochlorite under ultrasonication and the pulp system injected with Indian ink. The teeth were rendered clear by demineralization and immersion in methyl salicylate. The following observations were made: (i) number of roots and their morphology; (ii) number of root canals per tooth; (iii) number of root canals per root; (iv) root canal configuration in each root using Vertucci's classification, with additional modifications; and (v) presence and location of lateral canals and intercanal communications.Of 118 mandibular first molars, 13% had a third disto-lingual root. In three-rooted teeth, 80% of the main distal roots and 100% of the disto-lingual roots had type 1 canal systems. Of 60 mandibular second molars, 10% had C-shaped roots, the majority of which had type 1 (33%) or type IV (33%) canal systems. Of 173 third molars, 68% had two separate roots, 20% had fused roots and 11% had a single C-shaped root; the majority had two canals (61%).This study suggests that Thai molars exhibit features of both Caucasian and Chinese teeth.