Determining the interchangeability of KaVo PROTAR semi-adjustable articulators

Objective: Interchangeable articulators are crucial for a precise clinical outcome. Lack of interchangeability will affect the accuracy of the occlusion of prosthetic restorations. The objective of this study was to evaluate the interchangeability of KaVo PROTARevo articulators. Method and Materials: KaVo PROTARevo semi-adjustable articulators in routine use were employed. Identical casts were transferred among the articulators and the distance between casts was measured using digital photos of sagittal and frontal aspects of each articulator by two independent examiners. Interchangeability was assessed and analyzed by designated software. Results: Inter-examiner reliability was found to be high. Of 231 possible pairs of articulators only 27 pairs were found to be interchangeable (less than 166 µm in all measured dimensions), and of the other 204 pairs of articulators at least one of the dimensions measured was larger than 166 µm. Conclusion: The majority of articulators tested did not pass the 166-µm criterion to establish them as interchangeable. Therefore, in order to maintain accuracy while producing restorations, it is advisable to use the same articulator throughout the entire process, both at the clinic and in the dental laboratory. Keywords: articulator, interchangeability, occlusal adjustment, occlusion, prosthodontics