Abstract
Recently, Bis-GMA-Tri-EDMA based composite resins have been widly used as a restoration material for tooth. However, it has been pointed out that the mechanical properties of these resins, such as elastic modulus and frictional wear, are obviously inferior to those of metal materials. Therefore, the author examined the relationship between the amount of residual monomer, which deteriorates the mechanical property of the cured material, and the frictional wear of its material.
All specimen were immersed into distilled water (37°C) for a constant period after polymerization, according to the experimental conditions, and each measurement was also carried out in water at a temperature of 23±0.5°C. The amount of residual monomer in the cured resins decreased markedly with a time after the polymerization manipulation and attained the minimum value of the residual monomer at a week after that.
On the other hand, the surface hardness of cured resins increased considerably as the time proceeds, and an adequate negative correlation was estimated between the amount of residual monomer and surface hardness of the cured resin (r=-0.96). In addition, a significant correlation was also estimated between the amount of residual monomer and the magnitude of the frictional wear loss of the cured resin (γ=0.87). It was seen that the frictional wear loss diminished significantly according to the decrease of residual monomer and to the increase of filler content to the resin.
