This study examines the impact of different 3D printing technologies on the accuracy of implant positions in printed dental models, a crucial factor in implant-supported prosthetics. A standardized titanium model with three bone-level implants was scanned using an industrial scanner to create a virtual reference model. Ten intraoral scans of the same model were performed, and the generated STL files were used to design physical models printed with three different 3D printers: two utilizing digital light processing (DLP) technology and one employing stereolithography (SLA) (n = 30). The printed models were then rescanned, and deviations from the reference STL file were analyzed. Results showed that the SLA printer exhibited the highest deviations (0.26 ± 0.17 mm), whereas the DLP printers demonstrated greater accuracy, with one DLP system (0.07 ± 0.02 mm) performing slightly better than the other (0.12 ± 0.13 mm). The SLA printer exhibited the most significant errors in the vestibulo-oral and occlusal-apical directions. The findings suggest that DLP printers offer superior precision for implant-supported restorations in digital workflows. Clinically, the choice of 3D printing technology significantly impacts model accuracy, emphasizing the importance of selecting the appropriate printer based on the required precision.

The objective was to evaluate the trueness of interocclusal registration obtained with three intraoral scanning systems versus a conventional impression and bite registration in fully dentate patients. Twenty adults with complete dentitions and Angle Class I occlusion were enrolled. Complete-arch scans were obtained with Primescan, iTero Element, and TRIOS 4, followed by bilateral virtual interocclusal registration. Conventional impressions and polyvinyl siloxane records were used to fabricate stone casts, digitized with a laboratory scanner with the record and after manual articulation in maximum intercuspation. Industrial scanner datasets served as participant-specific references. Three-dimensional deviations were analyzed by repeated-measures ANOVA and Holm-adjusted paired t-tests (α = 0.05). The conventional workflow with an interocclusal record showed the greatest deviation (797 ± 308 μm; p < 0.001). Manual articulation (331 ± 167 μm) did not differ significantly from Primescan (262 ± 120 μm), iTero Element (256 ± 101 μm), or TRIOS 4 (325 ± 168 μm) (p ≥ 0.223); no differences were found among scanners under the conditions of this study (p ≥ 0.468). Virtual interocclusal registration showed greater trueness than the conventional workflow with a physical record, whereas manual articulation performed comparably to digital workflows. These conclusions apply only to fully dentate patients with stable occlusal support and maximum intercuspation.

Scan-assisted interocclusal registration may vary with record extent and occlusal support. Using separately fabricated high-hardness vinyl polysiloxane (VPS) records, a fixed bilateral buccal intraoral scanner (IOS) acquisition protocol, optical reference articulations, and position-level three-dimensional analysis, this in vitro study compared prepared-tooth (Hard-Prep) and complete-arch (Hard-Arch) records across three support configurations and assessed a no-record IOS workflow. Ninety VPS-based and 45 no-record IOS acquisitions were analyzed. VPS records were fabricated under a 3.0 kg load; measurements used a 1.0 kg load. Overall three-dimensional deviation (dXYZ) was averaged over five mandibular positions. Log-transformed dXYZ was analyzed by ordinary least squares with Holm-adjusted contrasts. The Hard-Arch/Hard-Prep contrast was not statistically significant under bilateral extended support. Hard-Arch showed higher dXYZ under unilateral extended support (ratio, 1.75; 95% confidence interval (CI), 1.54–1.99; p < 0.001) and unilateral limited support (ratio, 1.58; 95% CI, 1.39–1.80; p < 0.001). In the no-record workflow, unilateral extended support exceeded bilateral extended support (ratio, 1.50; 95% CI, 1.31–1.72; p < 0.001), whereas unilateral limited support was lower than unilateral extended support (ratio, 0.68; 95% CI, 0.59–0.77; p < 0.001). Prepared-tooth records yielded lower deviation in both unilateral configurations, while the no-record workflow varied with support configuration.