Effect of vacuum sealing and heat treatment on the accuracy of castable resin patterns for denture frameworks fabricated using digital light processing.

BACKGROUND/PURPOSE: Although three-dimensional (3D) printed castable resin patterns have been used for denture framework fabrication, resin deformation influences accuracy. This study aimed to verify the effect of vacuum sealing and heat treatment on the accuracy of castable resin patterns for denture frameworks fabricated using digital light processing (DLP). MATERIALS AND METHODS: A simplified major connector was digitally designed on the master cast simulating the maxillary palate. Based on the different post-processing procedures and durations after post-processing, thirty-six specimens were divided into six groups after being printed using a DLP printer within castable resin materials. Specimens were subjected to one of three post-processing methods after rinsing: post-curing directly (control), vacuum sealing before post-curing (VS), or vacuum sealing followed by heat treatment before post-curing (VSH). The specimens were subsequently scanned 1 or 3 h after post-processing (n = 6). The trueness and precision were subsequently analyzed by calculating root mean square (RMS) values. A two-way analysis of variance and Tukey's post-hoc test were performed (α = 0.05). RESULTS: Although the duration after post-processing did not have a statistically significant effect on the trueness and precision (P > 0.05), different post-processing procedures demonstrated a statistically significant effect on the trueness and precision (P <0.001). The VSH group demonstrated the lowest RMS value of trueness and a lower RMS value of precision than the VS group (P <0.05). CONCLUSION: Vacuum sealing combined with heat treatment significantly improved the trueness and precision of DLP-printed castable resin patterns for dentures.