Effects of heat and pH in silanation process on flexural properties and hydrolytic durabilities of composite resin after hot water storage

The objectives of this study were to evaluate the effect of heat application after silanation and the pH effect of silanated solution on flexural properties and hydrolytic durability of experimental composites. A spherical-shaped filler was silanated with 0.66 mass % of gamma-MPTS in 70 vol% ethanol solution. For the heating effect, the filler was heated after silanation for 3 hours at 50degreesC, 80degreesC and 110degreesC. For the effect of pH, ethanol solution with HCl solution of pH 1, 2 and 4 were used. All fillers were mixed to make photopolymerized experimental composite resins. All specimens after immersion in 37degreesC water for 24 hours were additionally immersed in Soxhlet's extractor for another 1, 7 and 28 days. A three-point bending test was performed in 37degreesC water. The heat application of 50degreesC and 80degreesC increased flexural strength while heat of 110degreesC and pH showed no effects on flexural properties at p<0.05.