Impact of intaglio surface depth and scanning technology on the trueness of complete denture scans using intraoral scanners.

To evaluate how the depth of the intaglio surface on the denture and the scanning method influence the trueness using two types of intraoral scanners (IOS) for complete dentures. Four complete denture types (Extra-deep, Deep, Moderate, Shallow) with varying intaglio surface depths (Extra-deep > Deep > Moderate > Shallow) for the maxilla and mandible were designed using two computer-aided design software, resulting in 8 denture models. Reference data were obtained using a laboratory scanner (D2000). Each denture was scanned eight times using two IOSs: a confocal microscopy-based scanner (Trios 5) and a dual-triangulation-based scanner (i700), resulting in 64 scans per IOS (128 scans in total). Scan data were superimposed using three-dimensional editing software, and the root mean square (RMS) was calculated to assess trueness. Statistical analyses included the Shapiro-Wilk test for normality and two-way analysis of variance with Bonferroni correction (α=0.05). For Trios 5, the RMS value for the Extra-deep was significantly higher than that for the Moderate and Shallow in both the maxilla and mandible. Furthermore, the Deep showed significantly higher RMS values than the Shallow in the maxilla. For i700, the RMS values did not significantly differ among the denture types. Across all denture types, the RMS values for i700 were significantly higher than those for Trios 5. The depth of the intaglio surface on the denture influenced trueness when using the Trios 5. The Trios 5 showed higher trueness than the i700 did across all denture types.