Three dimensional changes in full dentures during processing. Part I Displacements of teeth and deformations of surface contoures.

In this study, the authers set-up the origin and coordinate axes outside of the denture and working cast, and measure the displacements of teeth and deformations of surface contoures during process of full denture construction using heat-curing resin (Acron and Lucitone 199).The conclusions are follows:1. Displacements of teeth1) Horizontal directionIn all dentures, the teeth displace toward inside and forward after cured. The displacement of posterior is larger than the anterior.2) Vertical directionIn all dentures, the teeth displace toward occlusal surface. In upper dentures, the displacement of posterior is larger than the anterior, and in lower dentures, it's relation is conversely. After removed from the cast, the displacement is larger than before.2. Deformations of polished surface contoures (in upper denture)In all dentures, the polished surface deformes upward after cured. The deformations in center of palate and posterior border are larger than the others. After removed from the cast, particulary in case of Acron, the polished surface deformes upward more than before.