Effect of 3D-Printer Technology on the Trueness of Digital Analog Positions in Digital Implant Models: In Vitro Study

To evaluate the trueness of implant analog positions in digital implant models (DIMs) printed via two different technologies: direct light processing (DLP) and liquid crystal display (LCD).

In total, 21 replicate casts were reproduced from an educational implant model with six keyposition implants: 14 DIMs through the educational model (EM) scanning and 3D printing by DLP and LCD 3D printers (group DLP and group LCD; n = 7/group); and 7 stone models by pouring EM open-tray impressions (group Stone). All casts were scanned to generate their STL files. The STL of the EM laboratory scanning provided the reference data. Medit Compare deviation analysis software was used to assess the positional trueness of implant analogs. ANOVA for repeated measures and paired t test were used for intragroup comparisons, and the three groups were compared using one-way ANOVA and Bonferroni post hoc test (P ≤ .05).

Group DLP exhibited greater vertical deviations, and group Stone exhibited greater horizontal deviations (P ≤ .05). The highest deviation recorded was for the vertical displacement in group DLP (0.488 ± 0.090 mm), and the least was for group Stone vertical displacements (0.032 ± 0.008 mm; P ≤ 05). Comparing the mean difference of apex/shoulder vertical displacements between groups indicated greater tilting of the vertical axis in group DLP (0.504 ± 0.096), followed by group LCD (-0.285 ± 0.040) and group stone (-0.167 ± 0.026; P = .000).

Regarding implant analog positional trueness, the Stone casts are more accurate than the 3D-printed models; however, 3D-printed DIMs generated via intraoral scanning and printed using LCD technology showed close accuracy findings.