Effects of Operator Experience and Scanning Distance on Intraoral Scanner Accuracy

Aim: This study aimed to evaluate the effect of operator experience and scanning distance on the accuracy of the intraoral scanner in terms of trueness and precision. Material and Methods: Reference data were obtained by scanning a partially edentulous gypsum model with implant analogs in regions 15, 16, 26, and 27 using a desktop scanner. Two expert dentists, one experienced and one inexperienced, performed test scans using the Trios 5 scanner. All data were transferred to analysis software. The scan bodies in the test scans were superimposed with the reference scan bodies for trueness measurement using a best-fit algorithm, calculating the deviation between the datasets. Precision measurement involves aligning the test scan data with each other using the same method. The effect of operator experience and scanning distance on scanner accuracy was evaluated using independent-sample t-tests. Results: Full-arch scans exhibited higher trueness and precision deviations than partial-arch scans. For partial-arch scans by the experienced operator, the mean trueness deviation was 7.45µm, compared to 55.56µm for full-arch scans (p<0.001). Inexperienced operator results were 7.60µm and 58.90µm, respectively (p<0.001). Operator experience had no significant effect on trueness. For partial-arch scans performed by the experienced operator, the mean precision deviation was 2.73µm, compared to 33.87µm for full-arch scans (p<0.001). Inexperienced operator results were 3.36µm and 39.79µm, respectively (p<0.001). Operator experience significantly affected precision in partial-arch scans (p=0.044) but not in full-arch scans (p=0.563). Conclusion: Scanner accuracy decreased with increasing scanning distance. The effect of operator experience on scanner accuracy was insignificant.