[Adaptability of composite resin inlays. 1. Adaptability to the experimental MOD cavity prepared in an acrylic block].

The adaptability of composite resin inlays was examined. CR Inlay and INLAY/ONLAY were used as materials. After the CR Inlay was polymerized in a U-form metal mold, the dimensional changes were measured before and after heating. Furthermore, the composite resin inlays made according to the manufacturer's instructions were cemented in an MOD type cavity and the film thickness of the cement was measured. The polymerization shrinkage of CR Inlay was 0.63% in the inside of the inlay and after heating it increased to 0.71%. The film thickness of the cement in the case of CR Inlay was more than 250 microns and that in the case of the INLAY/ONLAY was more than 750 microns in the MOD type cavity. Dentacolor XS (a box type photo generator) was better than Wite Lite (a handy type photo generator) for the polymerization of CR Inlay. Because of the poor adaptation of the inlays and the difficulty in removing a inlay from a stone model for CR Inlay, perhaps polymerization shrinkage of the inlay should be compensated in some way.