Tooth movement in maxillary complete dentures fabricated with fluid resin polymer using different investment materials


Background: This study investigates the effect of different investments on tooth movement of new fluid resin andcompares the results with that of heat-cured resin. Besides, comparison between the right and left changes invertical distances of maxillary complete dentures that had been made.Materials and methods: A maxillary complete denture with acrylic teeth was waxed to full contour on the mastercast and replicated to make 40 wax dentures. Metallic reference points were placed for linear and verticalmeasurements. Ten dentures were allocated for each of 4 groups; group I was processed using conventional heatcuredresin (RegularTM), group II was processed with cold-cured fluid resin (CastavariaTM) in a reversible hydrocolloidmold, group III and IV processed with the same fluid resin in addition silicone duplicating mold, and in a dental stonetype III mold, respectively. Measurements had been made at the wax stage immediately before flasking, 24 hoursafter deflasking, and after decasting, finishing and storage in water at 37¢ªC for 1 week, the measurement had beenmade with a micrometer microscope accurate to 0.005 mm.Results: the results showed a significant tooth displacement in the different investments and in different types ofacrylic resin used in this study. The right and left vertical measurements did not differ significantly from each other.Conclusions: Maxillary dentures processed from fluid resin in silicone molds, produce the least linear dimensionalchanges comparable to those constructed from heat-cured resins. The decrease in vertical dimension of occlusionstill exists as a disadvantage of the new fluid resin systems