Purpose: This study aimed to analyze a possible gain in accuracy in intraoral scanning systems by manufacturer calibration. Materials and Methods: A master model was scanned tenfold with a Lava Chairside Oral Scanner (3m ESPE) and a CEREC Bluecam suspected to be decalibrated. Thereafter the scanners were calibrated and the model was scanned again. An iTero system served as comparison. All scans were compared to the master scan, and the mean deviation (entire arch, single tooth) was calculated. Results: After calibration, there was a significant gain in accuracy for both systems. Conclusions: Intraoral digital scanners may be sensitive to hardware decalibration invisible to the user and therefore need maintenance.