Periodic evaluation of the occlusal vertical dimension of maxillary dentures from the wax trial denture through 48 hours after polymerization.

Abstract

This study measured the effects of commercial resin type on maxillary complete dentures with monoplane teeth by periodically comparing the occlusal vertical dimension of the polymerized dentures with the baseline, wax trial denture fiducial measurements. Commercially available compression-molded, injection-molded, and fluid poly(methyl methacrylate) resins, as well as one compression-molded methyl acrylate ester copolymer, were evaluated. Ten dentures were fabricated from each resin using monoplane teeth. The occlusal vertical dimension at the articulator pin was measured at the wax denture stage for each specimen, and changes in occlusal vertical dimension for each denture were evaluated at a simulated laboratory remount, and at 0, 3, 6, 24, and 48 hours after a simulated clinical remount. Repeated measures analysis of variance (alpha = 0.05) and post hoc one-way factorial analysis of variance and Scheffe's F-Tests for each resin group were performed using ranks of raw data. Changes in the maxillary denture mean occlusal vertical dimensions were recognized throughout the evaluation periods compared with the wax-denture baseline, and time was a significant influence on displacement (p = .0001). Only the compression-molded poly(methyl methacrylate) dentures exhibited a mean laboratory remount occlusal vertical dimension that was significantly greater than the mean wax denture measurement, and all resin systems exhibited occlusal error that was significantly less than the laboratory remount measurements at 48 hours. At 48 hours, all resin groups exhibited mean occlusal vertical dimension changes that were less than 1 mm compared with the wax denture. Only compression-molded poly(methyl methacrylate) dentures exhibited a mean 48-hour clinical remount measurement that was statistically similar to the mean wax denture occlusal vertical dimension. Individual maxillary dentures from all resin types and at all intervals exhibited dimensional change. At the last evaluation period, the compression-molded poly(methyl methacrylate) showed no change in mean occlusal vertical dimension from baseline, whereas remaining groups exhibited occlusal vertical dimensions significantly less than baseline.