Precision and trueness of dental models manufactured by different 3D printers

Abstract

The aim of this study was to assess the precision and trueness of dental models printed with three-dimensional (3D) printers via different printing techniques, with a view to the potential clinical use of 3D printing models. Digital reference models were printed five times using the stereolithography apparatus (SLA), digital light processing (DLP), fused filament fabrication (FFF), and PolyJet technique. The 3D-printed models were scanned and evaluated for tooth, arch, and occlusion measurements. Precision and trueness were analyzed with root mean squares (RMS) for the differences in each measurement. The differences among models that had been repeatedly printed from the same 3D printer were compared to determine precision, and the differences between the reference dental model and the dental models printed from 3D printers were obtained to determine trueness. Statistical analysis was performed using one-way analysis of variance (α = 0.05). The following results were obtained: 1. Except in trueness of occlusion measurements, there were significant differences in all measurements among the four techniques (p < 0.001). 2. For overall tooth measurements, the DLP (76 ± 14 µm) and PolyJet (68 ± 9 µm) techniques exhibited significantly different mean RMS values of precision from the SLA (88 ± 14 µm) and FFF (99 ± 14 µm) techniques (p < 0.05). For overall arch measurements, the SLA (176 ± 73 µm) technique exhibited significantly different RMS values of precision from the DLP (74 ± 34 µm), FFF (89 ± 34 µm), and PolyJet (69 ± 18 µm) techniques (p < 0.05). For occlusion measurements, the FFF (170 ± 55 µm) technique exhibited significantly different RMS values of precision from the SLA (94 ± 33 µm), DLP (120 ± 28 µm), and PolyJet (96 ± 33 µm) techniques (p < 0.05). 3. There were significant differences in mean RMS values of trueness of overall tooth measurements among all four techniques: SLA (107 ± 11 µm), DLP (143 ± 8 µm), FFF (188 ± 14 µm), and PolyJet (78 ± 9 µm; p < 0.05). For overall arch measurements, the SLA (141 ± 35 µm) and PolyJet (86 ± 17 µm) techniques exhibited significantly different mean RMS values of trueness from DLP (469 ± 49 µm) and FFF (409 ± 36 µm) techniques (p < 0.05). The 3D printing techniques exhibited significant differences in precision of all measurements and in trueness of tooth and arch measurements. The PolyJet and DLP techniques were more precise than the FFF and SLA techniques, with the PolyJet technique exhibiting the highest accuracy.