TiO2-Nanofillers Effects on Some Properties of Highly- Impact Resin Using Different Processing Techniques

Background: The criteria of conventional curing of polymethyl methacrylate do not match the standard properties of the denture base materials. Objectives: This research was conducted to investigate the addition of TiO2 nano practical on impact strength, thermal conductivity and color stability of acrylic resin cured by microwave in comparison to the conventional cured of heat-polymerized acrylic resin. Materials and Methods: 120 specimens made of high impact acrylic resin were divided into two main groups according to the type of curing (water bath, microwave), then each group was subdivided into two groups according to the addition of 3% TiO2 nano-fillers and control group (without the addition of TiO2 0%). Each group was subdivided according to the type of test into 3 groups with 10 specimens for each group. Data were statistically analyzed using Student t-test to detect the significant differences between tested and control groups at significance level (P<0.05). Results: According to curing type methods, the results showed that there was a significant decrease in impact strength of microwaved cured resin, but there was no significant difference in the thermal conductivity and color stability of resin. In addition, by using nanofiller, there was a significant increase in the impact strength and color stability with the addition of 3% TiO2 nanofillers, but no significant difference was found in the thermal conductivity of the acrylic resin. Conclusion: The microwave curing of acrylic resin had no change in the color stability and thermal conductivity in comparison to the water bath, but the impact strength was decreased. The addition of 3% TiO2 improved the impact and the color stability, but the thermal conductivity did not change.