Effect of abutment tooth geometry on the accuracy of 2 intraoral scanners

Abstract

Aim: The aim of this in-vitro study was to evaluate the effect of abutment tooth geometry on the accuracy of two intraoral scanners. Methodology: The study was conducted using maxillary typodont. Six full coverage crown preparations were performed on central incisors, 1st premolars and 1st molars with known axial wall taper (6o and 12o) using dental parallelometer. Highly accurate table-top scanner (Identica T500) was used to obtain reference scan to the typodont. Two intraoral scanners (3shape Trios 3 and Medit i500) scanned the typodont 13 times to obtain total samples of prepared teeth (n=39) for each group. All scans were exported in standard tessellation language (STL) format. Measurements of trueness and precision for respective tooth preparation were evaluated using reverse engineering software for superimposition and deviation analysis. Comparison between groups was performed by using One-Way ANOVA test followed by Tukey`s Post Hoc test and Independent t- test. Results: Statistical analysis showed no significant difference in trueness between the two intraoral scanners. Trueness values were 39.9 µm and 41 µm for Trios 3 and Medit i500. Trios 3 was significantly more precise (23.6 µm) compared to Medit i500 (34.7 µm).