Comparative Evaluation of the Marginal Accuracy of Castable Resin Materials Fabricated Using Two Different 3D Printing Methods: An In Vitro Study

Background Advancements in computer-aided design and computer-aided manufacturing (CAD/CAM) technology have enabled the development of digital workflows for the fabrication of dental restorations. Three-dimensional (3D) printing technologies, such as Liquid Crystal Display (LCD) and Digital Light Processing (DLP), are increasingly being used for the fabrication of castable resin patterns. However, limited information is available regarding their marginal accuracy. Aim The aim of this study is to evaluate and compare the marginal discrepancy of castable resin patterns for porcelain-fused-to-metal (PFM) copings fabricated using the LCD (Sonic Mini 4K; Phrozen 3D, Hsinchu City, Taiwan) and DLP (Max 3D; Asiga, Alexandria, New South Wales, Australia) printing methods. Materials and methods An in vitro study was conducted using a standardized full crown preparation on a maxillary premolar typhodont tooth. The prepared tooth was scanned, and a coping was digitally designed using CAD software. The design was exported as a standard tessellation language (STL) file for fabrication of castable resin coping patterns using LCD and DLP printers, designated as Group A and Group B, respectively (n = 15 per group). Marginal discrepancy was evaluated at six standardized reference points using a digital microscope. The obtained data were subjected to statistical analysis. Results Group B demonstrated lower mean marginal discrepancy values compared with Group A. Statistical analysis revealed a significant difference between the groups (P < 0.001). The mean marginal discrepancy of specimens fabricated using the DLP printer was 48.7 ± 8.6 µm, whereas specimens fabricated using the LCD printer demonstrated a mean marginal discrepancy of 68.5 ± 7.6 µm. Conclusion Within the limitations of this in vitro study, castable resin coping patterns fabricated using both LCD and DLP printing methods demonstrated marginal discrepancy values within the selected clinically acceptable range under the conditions of the study. However, the DLP printer exhibited lower marginal discrepancy values compared with the LCD printer.