Impact of operator experience on intraoral digital scanning: A systematic review, meta-analysis, and meta-regression. Report of the Committee on Research in Fixed Prosthodontics of the American Academy of Fixed Prosthodontics

STATEMENT OF PROBLEM: How much operator experience influences intraoral digital scanning outcomes is unclear, as previous studies have shown inconsistent results. PURPOSE: The purpose of this systematic review, meta-analysis, and meta-regression was to answer the following 2 complementary research questions based on the population, intervention, comparison, outcomes, and study design (PICOS) framework: in intraoral scanning of dentate, partially edentulous, or completely edentulous patients, with or without dental implants, can differences be found between inexperienced and experienced operators, and can differences be found before and after receiving training sessions when assessing accuracy in in vitro studies, as well as in scanning time and patient satisfaction in randomized and nonrandomized controlled clinical trials (CCTs)? MATERIAL AND METHODS: Three databases (Embase, Medline, and The Cochrane Library) were systematically searched from their inception to March 2025 to identify studies addressing the PICOS questions. Risk of bias (RoB) was assessed using the ROB 2.0, ROBINS-I, and QUIN tools. The primary outcome measure was scanning trueness. Secondary outcomes included precision, scanning time, and patient satisfaction. Data were pooled and analyzed using mean differences (MDs) and prediction intervals (PIs) when significant heterogeneity was observed (P<.05). Subgroup analyses were conducted, when possible, based on clinical situation (dentate, partial edentulous, edentulous, single implant, 2 implants, and complete arch implant-supported prostheses), scan extension (sextant, half or complete arch impression), outcome measurement (root mean square, linear and angular deviation), and operator experience. A meta-regression was performed on the year of the scanner's market release, intraoral scanner (IOS), clinical situation, arch (maxilla and mandible), and outcome measurement to explore sources of heterogeneity. The certainty of the evidence (CE) was assessed using the GRADE system. RESULTS: Inexperienced operators showed lower trueness (MD 2.51 µm 95% CI:.16 to 4.86; P=.04; 8 in vitro studies; 720 scans on casts; CE: low), no difference in precision (MD -1.23 µm 95% CI: -4.97 to 2.50; P=.52; 3 in vitro studies; 280 scans on casts; CE: low), longer scanning time (MD 40.95 seconds 95% CI: 17.10 to 64.80; P<.001; 3 controlled clinical trials; 180 scans on patients; CE: low), and provided less patient satisfaction (visual analog scale: MD -12.69% 95% CI: -20.96 to -4.42; P<.001; 1 controlled clinical trial; 40 scans on patients; CE: very low) compared with experienced operator. After training, operators showed better trueness (MD -19.22 µm 95% CI: -26.29 to -12.15; P<.001; 2 in vitro studies; 120 scans on casts; CE: low), no change in precision (MD 0.34 µm 95% CI: -1.26 to 1.93; P=.68; 1 in vitro study; 40 scans on casts; CE: very low), and faster scanning times (MD -76.46 seconds 95% CI: -122.16 to -30.76; P<.001; 2 controlled clinical trials; 298 scans on patients; CE: low). The improvement in scanning time after training was greater in inexperienced operators compared with experienced ones (P<.05). CONCLUSIONS: Operator inexperience may minimally compromise scan accuracy, potentially increase scanning time and reducing patient satisfaction. Training sessions were associated with improved accuracy and efficiency in intraoral scanning.