A comparative study of changes in vertical dimension of occlusion using four different investing methods

Abstract

Statement of problem Acrylic resin complete dentures undergo dimensional changes during polymerization. Alternation in type of investment mediums and laboratory procedures can affect vertical dimension of occlusion. Purpose The purpose of this study was to compare changes in vertical dimension of occlusion of simulated complete dentures using four different investing methods in compression molding technique. Materials and Methods Four test groups with 10 sets of complete dentures each were evaluated. Flasking were done in four groups: Group 1: PlasterMixed, Group 2: PlasterStoneMixed, Group 3: PlasterMixedStone, Group 4: PlasterStonePlaster. All experimental groups were compression molded with denture base resin. Changes in occlusal vertical dimension were measured before and after denture processing. Collected data were analyzed with analysis of variance and Tukey's test at 95% level of confidence (p=0.05). Results The Mean of VDO changes in different groups were: group 1 (0.860 ± 0.839), group 2 (0.710 ± 0.585), group 3 (1.548 ± 0.951) and group 4 (0.578 ± 0.686). Conclusion There was significant difference between all tested groups. Less dimensional change was observed in the simulated dentures tested when they were invested with PlasterStonePlaster than when flasked with other investing techniques.