Effect of flask closure method on occlusal vertical dimension of complete upper and lower dentures

Abstract

The movement of teeth during processing of complete dentures disturbs the harmonious occlusal scheme established at the final wax try-in stage. Aims and objectives: to investigate the effect of RS flask closure on occlusal vertical dimensions of complete dentures. The mean occlusal vertical dimension of complete maxillary and mandibular dentures fabricated by the conventional flask closure were measured and compared with that of dentures fabricated by RS flask closure. Design: A pre-test post-test control group experimental design. Methods: Thirty sets of complete maxillary and mandibular wax trial dentures were randomly assigned to experimental groups. Fifteen sets were assigned to conventional flask closure and the remainder to RS flask closure. Compression molding with a long curing cycle was performed for the processing of the dentures. Pre-processing and post-processing occlusal vertical dimensions were determined. Results: The mean occlusal vertical dimensions of wax trial dentures assigned to either group were similar. The data produced substantial evidence to reject the null hypothesis that the post-processing mean occlusal vertical dimensions of both groups were equal. Conclusion: The occlusal vertical dimensions produced by dentures clamped by the RS flask closure were significantly less than those produced by dentures clamped by the conventional flask closure.