The implementation of intraoral and extraoral computer-aided-design and computer-aided-manufacturing (CAD/CAM) systems in prosthetic dentistry has simplified the procedure, shortened the period of design and manufacture and improved accuracy and aesthetic properties of dental restorations. Three-dimensional (3D) digitisation has become an adequate replacement for conventional dental impressions. The market offers a variety of diverse optical intraoral and extraoral CAD/CAM systems equipped with digitisation devices that are based on different working principles. The main goal of this research is to determine whether precision and accuracy differ among optical digitisation devices. The research includes five high-end devices: Cerec AC, Cerec InEos, Trios, KaVo Everest and Sinergia Scan. The evaluation methodology of the experiment is based on CAD inspection. The results, obtained from accuracy and precision measurements with tolerance levels of 0.01, 0.25 and 0.05 mm, indicate that there is a difference in accuracy and precision between optical digitisation devices based on different working principles.