ABSTRACT
Aim: The purpose of this study was to evaluate the accuracy of digital impressions taken with two different intra-oral scanners (with and without optical powder), by dentists with different level of experience. Material and Methods: Two intra-oral scanning devices (Apollo DI and Cerec Omnicam, Sirona Dental GmbH, Germany) were used to obtain a digital cast from scanning different preparations on a maxillary typodont. Three operator groups scanned five crown preparations using both powder and powder-free scanning systems. One group consisted of fourth year dental students, a second group consisted of prosthodontic residents, and third group consisted of prosthodontic specialists. The precision of spray application and impression expertise was compared between the three groups. Results: The most frequently encountered errors were non-linear powder application, inappropriate intra-oral scanner manipulation, and insufficient digital data for crown fabrication. Conclusion: Experience is needed in order to achieve high quality digital impressions. A prosthodontic specialist avoided incorrect manipulation of an intra-oral camera, uneven application of powder spray and achieved a better marginal fit.
