Caspian Journal of Dental Research

Introduction: Accurate impressions are essential for implant restorations. Intraoral scanners (IOS) have become well-established for capturing digital impressions. The aim of this study was to evaluate the trueness and precision of IOS in capturing implant positions in a partially edentulous maxilla.
Methods & Materials: Six implant analogs (DIO Implant. UF) in three maxillary acrylic models with Kennedy class 2 edentulousness (in canine, premolars, and molars area) were placed in three groups A: 10 mm inter-implant distance (IID), B: 20 mm IID and C: 30 mm IID. After fixing the scan bodies, 10 digital impressions were recorded for each three models using IOS (TRIOS 3Shape). In addition, one scan per model was performed with the laboratory scanner (Smart Optic Activity 885), and STL (Standard Tessellation Language) files were collected. All files were analyzed using GeoMagic Control software. Accuracy was assessed by comparing IOS data with high-precision laboratory scanner data and the repeatability of IOS within groups.
Results: Inter-implant distance reduced IOS trueness between all three groups significantly (p < 0.001). The accuracy was greatest at the 10 mm inter-implant distance through IOS. Mean IOS precision was higher in the 10 mm group, but this difference was not significant.
Conclusion: Despite in vivo limitations, this study shows that larger inter-implant distances reduce IOS trueness and precision for spaced implant impressions, potentially affecting digital impression accuracy and prosthetic outcomes.