Precision of 3D-printed splints with different dental model offsets.

INTRODUCTION: The purpose of this study was to assess the precision of 3D-printed splints generated from different dental model offsets. METHODS: Ten maxillary models were offset by given distances (0.05 mm, 0.1 mm, and 0.2 mm). Digital splints were created by means of the boolean operation. The physical splints were fabricated by means of digital light-processing (DLP) rapid prototyping technologies. A layer of impression material, which could be weighed by means of an electronic analytical balance, was placed in the airspace between the splint and the teeth. We also calculated the shell-to-shell deviations by measuring the 3-dimensional (3D) euclidean distances between the surface points of the scanned splints and the original digital splint and evaluating the results with color-mapping methods. RESULTS: There was a statistically significant difference in the amounts of impression material remaining in the airspace between the 0.0-mm group and the 0.05-mm, 0.1-mm, and 0.2-mm groups (P < 0.05), between the 0.05-mm and the 0.1-mm and 0.2-mm groups (P < 0.05), and between the 0.0-mm group and the 0.05-mm, 0.1-mm, and 0.2-mm groups (P < 0.05). There was a statistically significant difference in shell-to-shell deviations between the 0.05-mm and the 0.1-mm and 0.2-mm groups (P < 0.05). CONCLUSIONS: 3D-printed splints generated from offset dental models (offset 0.05 mm, 0.1 mm, and 0.2 mm) can fit better on the teeth than splints from no-offset dental models. An offset of 0.1 mm is the best choice of parameter for generating the splint.