Dimensional Stability of Additively Manufactured Maxillary Dental Casts for a Three-unit Fixed Partial Denture Fabricated with Different Build Orientations

Aim This study evaluated the dimensional stability of maxillary dental casts used for a 3-unit fixed partial denture across four build orientations (0°, 30°, 45°, and 90°). Material and method An upper jaw typodont with tooth preparations for a posterior 3-unit fixed partial denture was scanned by using an industrial scanner. The resulting scan file was nested with different orientations (0°, 30°, 45°, and 90°) and the casts were additively manufactured by using a digital light processing 3-dimensional (3D) printer (n = 7). Subsequently, all additively manufactured casts were scanned with the same scanner at 3 different time points (after fabrication, 1 month after fabrication, and 3 months after fabrication) and the deviations at the fixed partial denture region were assessed with the root mean square (RMS) method. Statistical analysis was performed using a generalized linear model at a significance level of α = 0.05. Results The build orientation and the time point significantly affected the RMS values (P