Influence of the implant scan body bevel location, implant angulation and position on intraoral scanning accuracy: An in vitro study

Purpose: To assess the influence of the scan body geometry bevel location and implant angulation and position of complete-arch implant digital scans. Material and methods: Two definitive casts with 4 implant analogs placed parallel (P group) or angulated up to 30? (NP group) were fabricated. Five subgroups were created based on the scan body geometry bevel position: facial, mesial, distal, lingual, or random (F, M, D, L, and R subgroup). Casts were digitized using a laboratory scanner (reference) (7Series Desktop Scanner) and an intraoral scanner (TRIOS 3). The implant position discrepancies between the reference and experimental scans were calculated. Data was analyzed using 3-way ANOVA and Tukey tests (alpha = .05). Results: The scan body geometry bevel position (P < .001) and the inter-implant distance (P < .001) were shown as significant predictors of the linear discrepancies obtained. The L subgroup had a significantly lower discrepancy compared with the other subgroups. Implant angulation (P < .001), the scan body geometry bevel position (P < .001), and the inter-implant distance (P < .001) were all significant predictors on the angular discrepancies obtained. Conclusions: The scan body geometry bevel location and implant angulation and position influenced the accuracy of the IOS tested. The lingual orientation obtained significantly better accuracy values compared with the other positions. The parallel implant analog position obtained better accuracy than the angulated positions. Lastly, the implant positioned in the dental arch where the intraoral digital scan was finished obtained significantly higher distortion than the contralateral implant.