Measurement of root surface area of permanent teeth with root variations in a Chinese population-A micro-CT analysis

Objectives: This study investigated the influence of root variations on the root surface area (RSA) by using micro-CT scans. Design: A total of 228 extracted permanent teeth (2-rooted and single-rooted maxillary first premolars, mandibular first premolars with non-Tomes' and Tomes' roots, 2-rooted and 3-rooted mandibular first molars, and 2-rooted and C-shaped mandibular second molars) were collected in a Chinese population and scanned using a micro-CT. In Mimics 15.01, 3D tooth models were generated, and the net and percent remaining RSA at various simulated attachment levels were measured. The data corresponding to attachment level were fitted to a linear function. Results: The mean total RSA for different root forms decreased in the following order: 3-rooted > 2-rooted > C-shaped > single-rooted. However, the differences were statistically significant (p < 0.01) only for 2-rooted vs. single-rooted maxillary first premolars, and 2-rooted vs. C-shaped mandibular second molars. Linear functions can perfectly fit in relating the attachment level to the net and percent remaining RSA. Conclusion: Micro-CT combined with Mimics software offers simple and precise technique for quantitative analysis of the RSA. Root variations may affect the total amount and vertical distribution of the net RSA. However, the degree of influence varies with the tooth type. (C) 2015 Elsevier Ltd. All rights reserved.