Changes in vertical dimension and occlusive contacts in complete dentures

Objectives: this study was to evaluate different flasking techniques using monomaxillary and bimaxillary flasks by microwave irradiation and water bath, in the occlusal vertical dimension (OVD) and the area of the occlusive contact (OC), before and after the curing. Methods: forty pairs of complete dentures were distributed into four groups of ten pairs each, according to the treatments: GI– cured by water bath and monomaxillary flasks; GII– cured by microwave irradiation and monomaxillary flasks; GIII– cured by water bath and bimaxillary flasks; GIV– cured by microwave irradiation and bimaxillary flasks. For the measurement of the OVD, it was used a table in which the articulator and the digital caliper was positioned, and three measurements were made before and after the curing. The area of OC was measured by using the software Qwin 550 (Leica®), each pair of denture was measured three times before and after the curing. Data were submitted to analysis of variance and Tukey test at 5% significance level. Results: the results demonstrated that all groups showed positive percent variation for the OVD: GI=1.92%; GII=2.92; GIII=2.27% and GIV=2.72%, and there were significant statistical differences between GI and GII (p=0.083). There weren't statistical differences with regards to the data of the area of the OC, between the upper and lower models. Except GII, in the upper models, every group showed reduction of the area of the OC. Conclusion: 1) the occlusal vertical dimension changed in all groups independently of curing method; 2) the group GII showed the lowest percent variation of the occlusal vertical dimension; 3) the group GI showed the highest percent variation of the occlusal vertical dimension; 4) there weren't statistical differences between the groups regarding the area of the occlusive contact; 5) all the groups, except GII, showed decreased area of occlusive contact after laboratorial processing