Dimensional Stability of Printed Dental Model: Stability over Time at Different Storage Temperatures

Background and Objectives: Dental models are essential for diagnosis and prosthetic treatment planning and have traditionally been fabricated from gypsum. With the growing adoption of digital workflows, 3D-printed dental models are increasingly used; however, concerns remain regarding their dimensional stability over time. This study evaluated the temporal dimensional changes of gypsum and 3D-printed dental models under different storage conditions and assessed the uniformity of these changes across the models. Methods: A fully dentate maxillary typodont was scanned to create a reference model. Sixteen gypsum casts (Type IV dental stone) and 48 3D-printed models from three materials were fabricated. Models were stored at either 4 °C or room temperature and rescanned at predefined intervals over 28 days. Dimensional accuracy was analyzed using 3D inspection software (Geomagic Control X 2022.1.0), with trueness measured by root mean square deviation and precision by standard deviation across the full arch and five predefined regions. Statistical analysis was performed using a Bayesian hierarchical linear model, with significance set at pd > 97.5%. Results: Printed models demonstrated significantly higher precision than gypsum models at baseline and day 28 under both storage conditions, with no significant differences among printed materials. In terms of trueness, selected printed groups showed lower deviations than gypsum at baseline, while one material exhibited the best performance at day 28. Gypsum models remained relatively stable over time, whereas printed models showed time-dependent, region-specific dimensional changes, primarily in posterior regions, with maximum deviations of up to 0.026 mm. Conclusions: 3D-printed dental models exhibit limited but nonuniform dimensional changes over time, while gypsum models remain comparatively stable. Localized distortions, particularly in posterior regions, should be considered when printed models are used for precise prosthetic applications.