Limpuangthip N, Tanvarasethee V, Lee JH* (Corresponding author). Influence of denture fabrication methods on trueness, number of photograms, and scanning time in extraoral digitization of maxillary complete denture with an intraoral scanner. J Prosthet Dent. 2026 Apr 22:S0022-3913(26)00250-7.
Abstract
Statement of problem: Denture duplication is often necessary to simplify new denture fabrication. The accuracy of extraoral digitization of dentures using an intraoral scanner (IOS) may be influenced by differences in material properties and surface textures among dentures fabricated using different methods. However, research examining this effect remains limited.
Purpose: The purpose of this in vitro study was to evaluate the influence of different denture fabrication methods on the trueness in the extraoral digitization of maxillary complete dentures with an IOS. The number of photograms and the scanning time were also assessed.
Material and methods: Three types of maxillary complete dentures classified by their fabrication methods were evaluated: metal-based heat-polymerized polymethyl methacrylate (PMMA) and prefabricated PMMA teeth, milled PMMA denture base and milled teeth, and 3-dimensionally (3D) printed denture base and 3D printed teeth. Scan powder was applied only to the metal surfaces of the heat-polymerized denture. Each denture was digitized using a desktop scanner (reference) and an IOS (n=10 per group). Trueness was analyzed using a 3D inspection software program for the whole denture, denture base, and tooth components. The number of photograms and scanning time were recorded. Data were analyzed using analysis of variance and the Kruskal-Wallis test (α=.05).
Results: The milled denture showed the highest root mean square (RMS) deviations (µm) for the whole denture (118 ±7) and denture base (139 ±9), followed by the metal-based group (95 ±6 and 108 ±8), with the 3D printed group demonstrating the lowest deviations (62 ±4 and 68 ±7) (P<.001). RMS deviations of prefabricated (51 ±2) and 3D printed teeth (54 ±5) were comparable and significantly lower than those of milled denture teeth (74 ±9; P<.001). The 3D printed group required the fewest photograms (P<.001) and the shortest scanning time (P=.011), whereas the milled and metal-based groups showed comparable results.
Conclusions: Trueness, the number of photograms and the scanning time of the extraoral digitization of maxillary complete dentures with an IOS significantly depended on denture fabrication methods. The 3D printed dentures showed the highest trueness, fewest number of photograms, and shortest scanning time. Milled dentures showed lower trueness but comparable numbers of photograms and scanning time relative to metal-based dentures with powder application. However, deviations for all groups remain within clinically acceptable thresholds.