Influence of Digital Workflows on Maxillary Complete Denture Base Fit Accuracy: A Prospective Clinical 3D Evaluation

Background: This study investigated the fit accuracy of maxillary complete denture bases (CDBs) fabricated using conventional, fully digital, and two hybrid workflows. Methods: Thirteen edentulous patients each received four maxillary CDBs produced via conventional (C), fully digital (FD), hybrid early (HE), and hybrid late (HL) workflows. Group C employed functional impressions and heat-polymerized polymethyl methacrylate (PMMA). Group FD utilized intraoral scanning (IOS), computer-aided design (CAD), and three-dimensional printing. The HE workflow combined digitally designed custom trays with conventional impressions, while the HL workflow digitized conventional master casts prior to digital fabrication. The master cast from the C workflow served as the reference. Deviations were calculated at 22 landmarks across six anatomical regions, with overall and regional analyses performed. Results: Group C exhibited the lowest deviation, followed by HE. HL and FD groups demonstrated significantly higher deviations (p < 0.001), with no significant difference between them. Regional variations were observed across most anatomical areas, except for the posterior palatal seal (p = 0.287). Conclusions: Clinical workflow significantly influences denture base fit accuracy. Conventional and hybrid early workflows provided more predictable adaptation, whereas hybrid late and fully digital workflows showed greater deviation, particularly in functional regions, potentially affecting clinical performance.