Evaluating the Accuracy of Intaglio Surface for Directly Fabricated Removable Denture Bases: An In vitro and Digital Study for a New Approach in Denture Fabrication

PURPOSE: This in vitro study aimed to evaluate intaglio surface accuracy for directly fabricated removable denture bases using different light- and dual-polymerized materials. MATERIALS AND METHODS: A standard edentulous mandibular model was scanned with an intraoral scanner to generate a reference model. Four dental materials were selected: a light-polymerized splinting resin, a dual-polymerized resin for denture base extension and repair, a functional denture relining material, and a light-polymerized acrylic resin for relining dentures (n=6 per material). A 3-dimensional (3D)-printed U-shaped negative template (2 mm thick) was filled with each material and directly adapted to the mandibular model. After polymerization, intaglio surfaces were scanned and superimposed onto the reference model. Trueness was assessed by comparison with the reference, and precision was evaluated by comparing scans within each material group. Mean absolute deviation (MAD) was calculated to quantify accuracy. Statistical analysis was performed using the Kruskal-Wallis test and Dunn post-hoc test with Bonferroni correction (α=.05). RESULTS: The light-polymerized splinting resin demonstrated the highest trueness and precision (lowest MAD: 0.114 ±0.019 mm and 0.113 ±0.021 mm, respectively). In contrast, the light-polymerized acrylic resin for relining dentures showed the lowest trueness and precision (highest MAD: 0.303 ±0.059 mm and 0.228 ±0.021 mm, respectively). These differences were statistically significant. CONCLUSIONS: Direct fabrication of denture bases using light- and dual-polymerized resins achieved clinically acceptable accuracy in all four tested materials, supporting the feasibility of this approach for denture base fabrication.