A novel algorithmic approach for automatic virtual articulation to avoid dynamic interferences in dental restoration designs.

Abstract

There is an ongoing debate about the benefits of the facebow and individual articulator settings in prosthodontics when compared with simpler methods. The present study aims to determine whether the implementation of novel algorithmic articulator concepts may be an alternative to avoid dynamic interference contacts during the design process of fixed posterior restorations, and to what extent the occlusal morphology of the restoration is affected. From a chairside CAD database, a total of 50 clinical patient cases documenting 61 planned fixed restorations in the posterior tooth region were selected. A common CAD software program was used for the automated knowledge-based design process. When designing the restorations, functional concepts were applied, including the pure static occlusion, the average articulation, three different articulator settings as a control, and a combination of a broad range of articulation parameters (the full range dynamic articulation). The resulting dynamic contact points were compared both visually and metrically with a monitoring software program. There is a highly significant difference in avoiding dynamic interference contacts when applying the full range dynamic articulation compared with the pure static occlusion (P < 0.001) and the average articulation (P < 0.001). Furthermore, the superimposition revealed that the surface of the restorations showed nearly no visual morphologic changes after virtually grinding-in the interpenetrating contact points. The full range dynamic articulation can be used for the design of small fixed posterior restorations to avoid most dynamic interference contacts without the need for determining individual parameters for each patient.