Powder and Powder-Free Intra-Oral Scanners: Digital Impression Accuracy.

Abstract

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. 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. The most frequently encountered errors were non-linear powder application, inappropriate intra-oral scanner manipulation, and insufficient digital data for crown fabrication. 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.