Impact of scanning interruptions on accuracy of implant-supported full-arch scans: An in-vitro pilot study

Purpose: To assess the impact of involuntary interruptions (simulating tracking loss by moving the scanner out of its focal distance) and voluntary interruptions (pressing the scanner's turn-on button) on the accuracy of implant-supported full-arch scans using an intraoral scanner (TRIOS 5, version 22.1.10; 3Shape; Copenhagen, Denmark). Materials and methods: An edentulous model with four implants was digitized with an industrial scanner (Artec Micro II; Artec 3D) to create a reference scan. Four groups (n = 30) were established based on the number of interruptions during scanning: Zero Group (no interruptions; control group), 6-V Group (six voluntary interruptions), 6-I Group (six involuntary interruptions), and 12-I Group (twelve involuntary interruptions). Primary outcome was accuracy assessed by the Root Mean Square (RMS) method. Secondary outcomes included scanning time and the number of photograms. Data were analyzed using one-way ANOVA and post hoc Tukey multiple comparison tests (alpha=0.05). Results: A total of 120 digital scans were conducted. The Zero group achieved a RMS error of 291 +/- 47 mu m, a scanning time of 68 +/- 6s, and 1320 +/- 129 photograms. 6-V group significantly reduced RMS error (MD -102 mu m [IC 95 %: -141, -63]), decreased scanning time (MD -20s [IC 95 %: -25, -17]), and reduced photograms (MD -415 photograms [IC 95 %: -506, -324]) compared to the control group (P<.001). Simulations of 6 or 12 involuntary interruptions did not affect accuracy compared to the control group (P>.05). Conclusions: Voluntary interruptions during scanning, achieved by pressing the scanner's turn-on button, appear to enhance accuracy due to image preprocessing, while involuntary interruptions had no significant impact on the accuracy of implant-supported full-arch scans.