A systematic review and meta-analysis (PRISMA 2020) pooling 15 in-vitro studies that
compared intraoral scanners used exactly as the manufacturer recommends against
scanners used with alternative techniques — different scan patterns, dry vs. wet fields,
ambient light, artificial landmarks, and scanning-aid sprays. Out of 3,268 records screened,
15 studies had usable data for pooling. Outcome measured: trueness (how close the scan is
to the real tooth) and precision (how repeatable the scan is).