Does the removal of the support structure affect the palatal accuracy of partial denture frameworks produced by three vat polymerization printing technologies?

To evaluate the effect of removing the support structure on the palatal accuracy of removable partial denture (RPD) frameworks fabricated using three 3D printing technologies: stereolithography apparatus (SLA), digital light processing (DLP), and liquid crystal display (LCD). A maxillary partial dentate resin cast was scanned with a laboratory scanner, and an RPD framework with a full palatal plate major connector was designed. The framework was 3D-printed in castable resin using three printer types: SLA, DLP, and LCD-based (n ​= ​7 per group). Resin frameworks were scanned before and after support removal, and palatal accuracy (trueness and precision) was evaluated with a 3D analysis program (Geomagic Control X). Combined ANOVAs (different levels) were used with Tukey HSD for data analysis (α ​= ​0.05). The palatal accuracy of RPD frameworks was significantly influenced following removal of the support structure, printing technology, evaluated areas, and their interactions ( p ​< ​0.001). Before removing the support structure, SLA frameworks showed the highest overall palatal trueness (43 ​± ​2.9 ​μm, p ​< ​0.001), while LCD had the highest precision (30 ​± ​6.2 ​μm). Following removal, the LCD group demonstrated the highest trueness (80.1 ​± ​9.9 ​μm) and precision (48.9 ​± ​5.3 ​μm). Palatal accuracy decreased in all groups following removal of the support structure, with SLA and DLP frameworks exhibiting the highest posterior palatal deviations. Before removing the support structure, LCD and DLP frameworks exhibited larger posterior palatal deviations. After removal, SLA and DLP frameworks showed the largest posterior palatal deviations, while anterior palate deviations remained minimal. Posterior palatal distortions following removing the support structure, particularly in SLA and DLP denture frameworks, could be minimized by optimizing support design, build orientation, and post-processing. • Removing support structures reduces palatal accuracy in 3D-printed frameworks, causing distortions in the posterior palate. • SLA frameworks have the lowest anterior palatal accuracy before and after removing the support structures. • SLA and DLP frameworks show the highest posterior palatal deviations after removing the support scaffolds. • Distortion patterns differ between anterior and posterior palatal regions. • Future research should optimize support design, build orientation, and explore automated removal methods to reduce distortions.