Metrological Protocol for Comparison of Digital and Analogic Articulators for Complete Dentures

This paper proposes a methodology to compare the trajectories from different articulators - both physical and digital - during lateral and protusive movements. In the case of digital articulators, the articulated models are digitally moved and exported in position; in the case of mechanical articulators, the models are locked into position and 3D scanned. The digital models in position, both digital and scanned, are aligned to a common reference system and a maxilla-based reference system is tracked. The trajectories are defined as interpolating splines through the maxilla-based reference system origins. A Gerber mechanical articulator and an “Artex CR adjustable” virtual articulator were compared. The repeatability of the mechanical trajectory is found to be less than 184 microns. The resting position of the two articulators is found significantly different meaning that a bias is introduced by the operator in the analogic protocol. The trajectories have significantly different shapes as expected coming from two different articulator models. The proposed methodology proved to be a valid means to compare different articulators.