Effect of different splinting configurations on the accuracy of complete-arch digital implant impressions: An in vitro study

Abstract

Background This in vitro study aimed to investigate the effect of different splinting configurations on the accuracy of digital impressions in fully edentulous arches. Materials and Methods Five configurations were tested on an edentulous maxillary phantom model containing six parallel implant analogs: G1: Non-splinted control, G2: Bilateral posterior splint, G3: Anterior splinted/posterior unsplinted, G4: Segmental independent splinting, and G5: Cross-arch. Ten scans were obtained per group; reference data were acquired using a high-accuracy industrial scanner (Solutionix C500). Point-based RMS (Root Mean Square), surface RMS, and angular deviation (ΔAngle) were calculated using Geomagic Control X. ART ANOVA and one-way ANOVA with Bonferroni-corrected post-hoc tests were applied (α=0.05). Results Significant differences among groups were detected for all parameters (p<0.001). In surface RMS, G5 exhibited the lowest deviation (0.62 ± 0.15 mm) and G2 the highest (1.27 ± 0.10 mm) (ηp2=0.793). In point-based RMS, G4 showed significantly higher deviation compared to G2, G3, and G5 (0.05 vs. 0.02-0.04mm). Regarding angular deviation, G2 showed the highest and G5 the lowest values (0.26° vs. 0.16°); the anterior and premolar regions demonstrated significantly higher angular deviation than the molar region (0.29-0.34° vs. 0.14°). Conclusions The effect of splinting on scanning accuracy was found to be parameter-dependent; G5 was superior in surface RMS and angular deviation, yet no configuration achieved consistent superiority across all parameters. The anterior-premolar region was identified as the highest-risk area for accuracy across all configurations, exhibiting the greatest angular deviation values.