Abstract
The physical properties of 2 kinds of self-curing resins for duplicating dentures (FL, RE) were compared with self-curing relining resin (RR) and a heat-curing denture base resin (AC).
The bending strengths were: RE: 277.3±69.3Kg/cm2, RR: 387.3±67.4Kg/cm2, FL: 684.6 ±47.9Kg/cm2 and AC: 593.1±33.77Kg/cm2, respectively. The knoop hardness numbers were: RR: 11.2±0.5, RE: 11.8±1.3, FL: 14.1±0.5 and AC: 18.0±0.6, respectively. The fluidity of FL is the best, RE is next, and RR is the worst.
The quantities of water sorption were FL: 0.65±0.19mg/cm2, RR: 0.63±0.11mg/cm2 and RE: 0.47±0.12mg/cm2, respectively. The rates of line shrinking were: FL 0.32±0.07%, RR: 0.32±0.04% and RE: 0.30±0.05%, respectively. Surface roughness (Ra) were: RR: 0.08±0.01μm, RE: 0.10±0.02, μm, FL: 0.11±0.01 μm and AC: 0.07±0.01μm, respectively. The results of detail reproducibility of FL is the best. From SEM observation of polished surface, heat curing resin a smooth suface. Numerous porosities were seen on the surface of RE, FL and RR.
From these results, there were no obvious differences in physical properties between self-curing resin for duplicating dentures and self-curing relining resins. However, self-curing resins for duplicating dentures were inferior in surface and physical properties compared with heat curing resins, so should not be used for long periods in the oral cavity.
