Lithium disilicate crowns were fabricated to fit an in vitro cast of a single human premolar. The purpose of the study was to evaluate with micro-computed tomography the marginal fit of lithium disilicate crowns fabricated with different chairside CAD/CAM systems (Cerec or E4D) or the heat-pressing technique.

No consensus exists concerning the acceptable ranges of marginal fit for lithium disilicate crowns fabricated with either heat-pressing techniques or computer-aided design and computer-aided manufacturing (CAD/CAM) systems. However improvements in materials and technologies are needed in order to overcome the actual drawbacks. The evidence of our clinical practice suggests that CEREC 3 chairside system allows to produce highly aes- thetic and reliable restorations in a single visit, while minimizing costs and patient discomfort during prosthetic treatment. Material selection was related to type of restoration. The biocopy project seemed to be the best tool to obtain func- tionalized surfaces and keep unchanged gnathological data.

The only drawback could be the sub- gingival placement of the margins compared with the supra/juxta gingival margins, since more time was required for the impression taking as well as the adhesive luting phase. Furthermore, a better acceptance level for the impression procedure has shown by the patients. The operator-dependent errors are minimized compared to the conventional prosthetic protocol. The CEREC system has shown many positive aspects that make easier, faster and less expensive the prosthetic workflow. Clinical procedures (tooth preparation, impression taking, adhesive luting), operational compo- nents and their capabilities as well as restorative materials used with CEREC 3 chairside system were reported. Benefits and limitations of this technology compared with the conventional prosthetic work- flow were also highlighted and discussed. The aim of this paper was to describe the CEREC 3 chairside system, providing the clinicians a detailed analy- sis of the whole digital workflow.

Cerec bluecam acquisition mechanism