Comparative study of condylar settings of three semiadjustable articulators.

The reproducibility of arcon semiadjustable Whip Mix, Denar Mark II, and Hanau 158 articulators was tested using multiple protrusive and lateral edge-to-edge wax interarch registrations made with an interocclusal device. Photographic and cephalometric tracings verified an identical angulation between the axis-orbital craniofacial reference plane and the maxillary occlusal plane for the subject and both the Denar Mark II and Hanau 158 articulators. This angle was 2.5 degrees less in the Whip Mix instrument. Three operators made three settings for each of 12 protrusive and 24 lateral interarch registrations for each articulator. Results showed significant differences between instruments. Whip Mix consistently gave the highest.angulations and Hanau 158 the lowest. For protrusive records there was no significant difference between examiners, but for lateral records a significant difference in examiner registration was found. For both protrusive and nonworking registrations, interaction was seen between instrument and operator and between instrument and registration, and a significant difference was seen between records. This study supports previous studies showing that semiadjustable articulators using interarch records have a low level of reproducibility and are subject to variables of instrument, operator, and occlusal records.