摘要：OBJECTIVE: The aim of this study was to evaluate the wear resistance and microhardness of three indirect composite resins after aging in different chemical solutions. MATERIALS AND METHOD: Three indirect composite resins, GrandioSO, Solidex and Signum, were used. Twenty specimens (diameter: 5 mm, thickness: 2 mm) were prepared from each composite material for the microhardness test and twenty-four specimens (diameter: 6.5 mm, thickness: 4 mm) were prepared from each composite material for the wear test. Solidex and Signum were polymerized at both sides for 180 s by using a 320-500 nm wavelength xenon stroboscopic light-curing unit. GrandioSO was polymerized 20 s by using a halogen light-curing unit. The specimens were then divided into four subgroups and stored for 1 week at 37 °C, in either distilled water, 0.02 N citric acid, 75% ethanol or artificial saliva (control). A pin-on-disc wear device was used to determine the wear rate of the composite resin. A load of 15 N was applied to the specimen surface (sliding velocity: 0.6 m.s -1 , sliding distance: 100 m, frequency: 1.5 Hz). Microhardness measurements were determined by using a Vickers testing device. RESULTS: Of all test materials, GrandioSO revealed the highest microhardness value and the values were statistically different compared with those of Signum and Solidex in citric acid, ethanol, artificial saliva or distilled water (p<0.05). The greatest wear value for Signum was obtained in distilled water (p<0.05). Solidex showed the greatest wear value in citric acid; however this value was significantly different only from that in artificial saliva (p<0.05). Similarly, GrandioSO revealed the greatest wear value in citric acid, and this value was significantly different only from that in distilled water (p<0.05). CONCLUSION: The effect of the different chemical media on wear and microhardness was found to vary according to the material; no correlation was observed between microhardness and wear measurements.
