Interchangeability of a Semiadjustable Articulator

Purpose: The purpose of this study was to investigate whether the interchangeability of new Hanau semiadjustable articulators fulfills the manufacturer's criterion (102 µm) in the mediolateral direction and the defined 166-µm criterion three dimensionally and whether the articulators maintain the same interchangeability as new articulators after a period of function. Materials and Methods: The spatial deviations in three dimensions of ten new, ten 18-month-old, and ten 30-month-old Hanau articulators were measured with a fieldinspection gauge and compared to those of a master articulator. Results: Compared to the master articulator, nine of 10 new articulators met the manufacturer's criterion of articulator interchangeability in the mediolateral direction. However, only four of the 10 articulators fulfilled the criterion for three-dimensional interchangeability. The articulators were found to be interchangeable among the groups when the spatial deviations of test articulators from the master articulator at the position of the lingual cusp of the right maxillary first premolar were compared. However, using the geometric mean deviations of test articulators, the 30- month group was not interchangeable with the new and the 18-month articulator groups. Conclusion: This limited study revealed that most of the articulators tested met the manufacturer's criterion of articulator interchangeability, but most did not pass the threedimensional interchangeability test. Clinicians should be aware of the amount of occlusal error in the range of 0.2 mm that may result from interchanging dental casts on the articulator system. The articulator system might be able to maintain the same level of interchangeability for up to 18 months of routine use.