Studying the accuracy of scanning prints and plaster models of clinical laser scanner

Today CAD/CAM - technologies are an integral part of prosthetic dentistry. In this respect, direct scanning of impressions enables to reduce time and costs. However, dictum on the effectiveness of the scanned impressions is contradictory. Therefore, the aim of this study is to compare the accuracy of the scanning impressions and plaster models by laser scanner Zirkonzahn S600 ARTI (Zirkonzahn, Italy). As a test model, we used Johansson gage - length standard, which has controlled value of 7 mm between the measuring planes. We have scanned 10 double-layer one-step A-silicone impressions (material Hydrorise, Zhermack, Italy) of the test model. From these impressions, we made 10 stone models: 5 from «Elit Rock» and 5 from «Elit Master» (Zhermack, Italy), which were also scanned. On each digital model, we performed 15 measurements of controlled length value between the measuring planes of the test model at a pitch of 1 mm. In such a way, in total, 300 measurements were carried out. The highest accuracy was shown in measurements of digital models from «Elit Rock» - 6,916 ± 0,015 mm, the lowest - in measurements of scanned impressions: 6,885 ± 0,012 mm. Digital models from «Elit Master» showed neutral result - 6,890 ± 0,019 mm. The results indicate that scanning of impressions allows us to achieve good results. A slight decrease in the accuracy of the scanned impressions compared with plaster models we associate with using a photosensitive spray. Development of stamping materials with the effect of light reflection seems to be highly promising for effective scanning of impressions.

CAD/CAM-technologies, scanning, impressions