Accuracy of Occlusal Contacts for Crowns with Chairside CAD/CAM Techniques

Information from the opposing dentition is used to design and fabricate occlusal contacts with a reasonable level of accuracy for a given restoration. The Dental Database with the Antagonist design process utilizes a bite registration to propose the construction of a virtual opposing model. The Articulation design technique utilizes a functionally generated bite registration to control both the maximum intercuspation and excursive contacts on the restoration. Correlation design technique offers the opportunity to copy the established occlusal anatomy to the preparation. Although these techniques offer a workflow to establish occlusal contacts with the Cerec system, there is a lack of quantitative data as to the accuracy achieved. Alternative techniques to control the occlusal contacts have been suggested which rely on "user customized design techniques" that recommend altered program settings, manual override of automated features in the software, or modification of the established software design programs. The purpose of this study was to measure the occlusal vertical discrepancy for various design techniques. Full crowns made using Dental Database with the Antagonist design technique had a significantly smaller occlusal vertical discrepancy than those made with Correlation. Dental Database with the Antagonist had a significantly smaller occlusal vertical discrepancy than all suggested alternative design techniques. Use of the Dental Database with Antagonist design technique provides the most accurate technique for establishing occlusal contacts with the Cerec 3D system. Keywords: CAD/CAM, occlusion, Cerec, software design