Evaluation of the Influence of Scanning Pattern and Scanning Technology on the Trueness and Precision of the Denture Reference Technique

PURPOSE: The present study investigated the combined influence of four different scanning patterns and two intraoral scanning (IOS) technologies (Confocal Ultrafast Optical Sectioning vs. Active Triangulation with Structured Light) on the trueness and precision of both the intaglio and cameo surfaces of a maxillary reference denture. MATERIALS AND METHODS: A maxillary complete arch reference denture was scanned using IOS technologies: Confocal Ultrafast Optical Sectioning (CUOS) and Active Triangulation with Structured Light (ATSL). Scanning was done 80 times with four strategies: APBOP (starting on the posterior intaglio surface), PABOP (beginning at the palatal aspect of the intaglio surface), BOPAP (starting on the cameo surface), and POBAP (beginning at the palatal cameo surface). Each strategy involved thorough scanning of various aspects, including occlusal surfaces, to capture the complete dentate arch. Distance-deviation values were calculated from comparisons with the STL reference model, and the data were analyzed using two-way ANOVA and Tukey's test. RESULTS: For the CUOS IOS technology, the POBAP scanning pattern exhibited the highest trueness (161 ± 6 μm) and precision (151 ± 7 μm), whereas the APBOP pattern showed the lowest trueness (183 ± 28 μm) and precision (171 ± 33 μm). For the ATSL IOS technology, the POBAP pattern also demonstrated the highest trueness (200 ± 32 μm) and precision (198 ± 32 μm), whereas the PABOP pattern showed the lowest trueness (241 ± 24 μm) and precision (239 ± 24 μm). The main effect of scanning technology was statistically significant (p < 0.001), with the estimated marginal mean (EMM) for CUOS being 171 μm, indicating greater trueness relative to ATSL (211 μm). A partial eta-squared value of 0.52 indicated that scanning technology explained approximately 52% of the total variation in trueness, representing a substantial effect size. CONCLUSION: CUOS consistently exhibited superior trueness across all scanning patterns compared with ATSL.