Number of main canals in a tooth: deciphering potential mechanisms.

Abstract

Although millions of root canal treatments are performed globally on a daily basis, factors that determine the number of main root canals in a tooth have not yet been elucidated. This review aimed to integrate the potential mechanisms involved in determining the number of main canals in a permanent tooth. Methods: We used the search terms “root canal number,” “root canal morphology,” “tooth morphology,” “root development,” and “root formation” to identify articles from the PubMed and Scopus databases. Results: Overall, it seems plausible that the potential mechanisms determining the number of main canals in a tooth are based on the orchestrating role of the Hertwig's epithelial root sheath in root development, although the specific molecular signals that govern the induction or repression of the diaphragmatic processes remain unknown. A multifactorial basis is possible considering the influence of genetic, epigenetic, and environmental factors. Conclusions: This review highlights potential mechanisms determining the number of main canals in a tooth; however, there is a dire need for molecular studies that help unveil these and other potential mechanisms involved.