Comparison of the Contact Surface Pattern Between Virtual and Milled Cerec 3D Full-ceramic Crowns

Purpose: The objective of this study was to compare resulting contact point patterns in the context of crown production with the Cerec 3D system. The contact surface patterns of full-ceramic crowns milled with the Cerec 3D system were examined for agreement with the corresponding virtually produced crowns. Materials and Methods: The agreement was determined with regard to the parameters number, size, position, and shape. Twenty-eight models were mounted centrally in a mechanical articulator. In these model cases, at least one second premolar and one first molar in the maxilla and mandible had to be prepared for crown production (preparation). A total of 50 teeth was prepared. Crowns were then designed with the aid of the Cerec 3D system. The crown designs were milled and integrated in the model. Silicone bite registrations, the contact point patterns of which were compared with the virtually designed crowns, were produced in static occlusion in the region of the crowns. Different evaluation methods were used for the comparison. Results: There was an agreement of 78% with regard to number, 76% in terms of localization, 65% regarding size, and 65% in terms of shape. Conclusion: It was thus confirmed that very good, highly reproducible results can be achieved with the Cerec 3D system. Keywords: CAD/CAM, Cerec 3D, fulceramic crowns, occlusal settling GEDAS - Greifswald Digital analyzing System