Influence of restorative material types on 3D printed aligner accuracy using intraoral scanners

OBJECTIVES: This study evaluated the effects of restorative materials and intraoral scanners on the mesh data quality of dental models and the accuracy of 3D-printed clear aligners. MATERIALS AND METHODS: Reference scan data were obtained with a tabletop scanner, while test data were collected using PrimeScan, Trios 3, and i600 scanners. Typodonts with metallic (gold) and non-metallic (zirconia) crowns were scanned. Data from each scanner were assessed for mesh quality and 3D accuracy. 3D printed aligners were subsequently printed based on each scanner's mesh data and evaluated. RESULTS: The i600 scanner had the highest mesh quality (0.81), followed by PrimeScan (0.76) and Trios 3 (0.74) scanners, whereas the restorative material had no significant effect on mesh quality (p < 0.05). Resin and zirconia crowns were generally measured larger than actual sizes, while gold crowns tended to be similarly measured or smaller. PrimeScan showed the highest accuracy for full-arch scans, while Trios 3 measured significantly smaller than the other two scanners p < 0.05). For gold crowns, i600 displayed the highest RMS value at 59 μm p < 0.05). Aligners printed from i600 scans showed the largest RMS value on the inner surface near gold crowns, averaging 94 μm. CONCLUSIONS: Types of restorative material and scanner can significantly affect the accuracy of 3D printed aligners and mesh quality. Metallic restorations can decrease accuracy with triangulation-based scanners. CLINICAL RELEVANCE: Clinical application of intraoral scanners that are less influenced by restorative materials, particularly metallic restorations, may improve the predictability of 3D-printed aligner treatment and help optimize clinical outcomes.