Journal of Prosthetic Dentistry, cilt.134, sa.3, 2025 (SCI-Expanded)
Statement of problem: The trueness of recording techniques in patients with maxillary defects for bilateral or unilateral implant placement remains unclear. Purpose: The purpose of this in vitro study was to evaluate the trueness of digital scans and conventional impression techniques in 2 maxillary defect models characterized by bilateral (Aramany Class VI) and unilateral (Aramany Class IV) implant placement. Material and methods: Two edentulous maxillary defect models (Class VI and Class IV) were designed with the 3-matic software program and fabricated with a 3D printer. Six implant analogs were placed in the Class VI model (bilateral), and 3 were placed in the Class IV model (unilateral). Digital scans were captured with Primescan (n=10) and TRIOS 4 (n=10) intraoral scanners (IOSs) and saved as standard tessellation language (STL) files. Conventional open-tray impressions were made with polyether, and the poured gypsum casts were also digitized into STL files (n=10). All STL files were aligned with reference digital casts through a software program (Geomagic Control X), and 3D deviations were assessed with root mean square (RMS) values. Statistical analysis was performed by using 2-way ANOVA and Tukey HSD tests (α=.05). Results: In the bilateral implant model, the conventional technique resulted in the lowest 3D deviation, whereas the Primescan scanner resulted in the highest deviation (P<.001). Compared with the conventional technique, the TRIOS 4 scanner resulted in significantly greater deviation in the unilateral implant model (P=.001), with no significant differences among the other groups (P>.05). For all the groups, the bilateral implant model resulted in higher deviation, although this difference was only significant for the Primescan and TRIOS 4 scanners (P<.001). Conclusions: Compared with IOSs, the conventional technique consistently demonstrated higher trueness, particularly in the bilateral implant model. These findings underscore the importance of selecting the appropriate technique based on the specific implant configuration to achieve optimal clinical outcomes.