Evaluation of Vertical Accuracy of Interocclusal Records

Purpose: The aim of this study was to evaluate four recording materials (polyether, polyvinyl siloxane, acrylic resin, and wax) for their ability to accurately record, maintain, and reproduce the vertical interocclusal relationship. Materials and Methods: A metallic apparatus was used to represent the opposing arches; its epoxy resin duplicate represented the working casts. The vertical discrepancies produced because of the presence of the records were measured both after repositioning them on the metal apparatus and after transferring them onto the casts. Two-way ANOVA was performed. Results: Closure through the interocclusal recording materials produced small vertical discrepancies ranging from 24 to 74 µm. When repositioned on the apparatus, the vertical discrepancies were greater. The lowest discrepancy was displayed by polyvinyl siloxane (101 µm) and polyether (107 µm), and the greatest was displayed by wax (168 µm). When records were transferred onto casts, the discrepancies were approximately 0.5 mm, without significant differences among materials. Conclusion: Closure through interocclusal recording materials and removal and repositioning of the records on the apparatus produced small vertical discrepancies with clinically insignificant differences between the materials tested. When records of all materials tested were transferred onto casts, vertical discrepancies of approximately 0.5 mm were found, which is of clinical concern.