Accuracy of optical scanning methods of the Cerec®3D system in the process of making ceramic inlays

Abstract

One of the results of many years of Cerec 3D CAD/CAM system technological development is implementation of one intraoral and two extraoral optical scanning methods which, depending on the current indications, are applied in making fixed restorations. The aim of this study was to determine the degree of precision of optical scanning methods by the use of the Cerec 3D CAD/CAM system in the process of making ceramic inlays. The study was conducted in three experimental groups of inlays prepared using the procedure of three methods of scanning Cerec 3D system. Ceramic inlays made by conventional methodology were the control group. The accuracy of optical scanning methods of the Cerec 3D system computer aided design-computer aided manufacturing (CAD/CAM) was indirectly examined by measuring a marginal gap size between inlays and demarcation preparation by scanning electron microscope (SEM). The results of the study showed a difference in the accuracy of the existing methods of scanning dental CAD/CAM systems. The highest level of accuracy was achieved by the extraoral optical superficial scanning technique. The value of marginal gap size inlays made with the technique of extraoral optical superficial scanning was 32.97 +/- 13.17 mus. Techniques of intraoral optical superficial and extraoral point laser scanning showed a lower level of accuracy (40.29 +/- 21.46 mus for inlays of intraoral optical superficial scanning and 99.67 +/- 37.25 mus for inlays of extraoral point laser scanning). Optical scanning methods in dental CAM/CAM technologies are precise methods of digitizing the spatial models; application of extraoral optical scanning methods provides the highest precision.