Research Information System
Journal of Prosthetic Dentistry, 2026 (SCI-Expanded, Scopus)
Statement of problem: Despite the growing use of digital workflows in prosthodontics, achieving accurate tissue adaptation for complete dentures remains challenging because of the limitations of intraoral scanners in capturing edentulous soft tissues. Clinical evidence comparing the adaptation accuracy of denture bases produced from conventional and different intraoral scanning technologies is lacking. Purpose: This prospective clinical study aimed to evaluate and compare the intraoral adaptation of maxillary complete denture bases fabricated by computer-aided design and computer-aided manufacture (CAD-CAM) technology using a conventional impression technique and 2 intraoral scanning systems in completely edentulous participants. Material and methods: Fifteen completely edentulous participants were included. Conventional impressions were obtained using zinc oxide eugenol paste after border molding, while digital scans were acquired using Medit i600 and TRIOS 4 scanners. Three corresponding 3-dimensionally (3D) printed denture bases per participant were fabricated and evaluated for tissue adaptation using a polyvinyl siloxane (PVS) impression material under a constant 20-N load. Best-fit alignment was used to determine misfit values across the entire surface, palatal, and vestibular sulcus regions. Data were analyzed using the Friedman and Conover post hoc tests (α=.05). Results: Median misfit values for the entire surface were 692 µm (conventional), 733 µm (Medit i600), and 731 µm (TRIOS 4), showing no significant difference. In the palatal region, the confocal-based TRIOS 4 demonstrated significantly better adaptation (486 µm) than the conventional method (608 µm; P<.01). Conversely, in the vestibular sulcus, the conventional technique produced significantly better adaptation (673 µm) than both digital systems (P<.001). Conclusions: Digital scans yielded similar overall accuracy to conventional methods but exhibited reduced border extension and inferior adaptation at the peripheral seal areas because of the mucostatic nature of intraoral scanning and the difficulties in recording movable soft tissues. While digital workflows offer efficiency and reproducibility, clinical modifications or digital border augmentation are necessary to ensure optimal retention and fit for complete maxillary dentures.