Comparative Evaluation of Surface Roughness of Injection Molded, CAD–CAM Milled and Rapid Prototyped Resin Denture Base Surfaces: An In Vitro Study

Purpose: The purpose of this study was to compare the surface roughness of resin denture base surfaces processed by injection molded, computer-aided design–computer-aided manufacturing (CAD–CAM) milled and rapid prototyped techniques. Materials and methods: Blender 3.4 software, a CAD software that allows creation of solid virtual models to exact specifications, was used for virtual designing of standard tessellation language (STL) files. A total of 78 acrylic disk specimens (10 × 3 mm) were fabricated using three different methods: injection molding, CAD–CAM milling, and rapid prototyping. Surface roughness analysis was evaluated using an atomic force microscope (AFM). A one-way analysis of variance (ANOVA) test was used for intergroup comparison, and the Bonferroni <i>post hoc</i> test was used for multiple pairwise comparisons within the groups. Results: The mean surface roughness values of CAD–CAM milled specimens were found to be the least (11.87 nm), followed by injection molded (20.50 nm) and rapid prototyped (30.89 nm) specimens (<i>p</i> = 0.001). The intergroup comparison revealed that surface roughness was highest in the rapid prototyped group, with the difference being statistically significant (<i>p</i> = 0.001). Conclusion: CAD–CAM milled specimens exhibited less porous surfaces than injection-molded and rapid-prototyped specimens, ensuring smooth surfaces that could decrease oral microbial attachment onto the denture base surfaces. Smooth denture surfaces play a critical role in successful treatment for elderly, immunocompromised, or systemically debilitated patients requiring removable complete dentures. How to cite this article: Balaraman G, Yogesh PB, Shafiullah RS, <i>et al.</i> Comparative Evaluation of Surface Roughness of Injection Molded, Cad–Cam Milled and Rapid Prototyped Resin Denture Base Surfaces: An <i>In Vitro</i> Study. Int J Prosthodont Restor Dent 2025;15(2):90–94.