Mechanical properties of three resin cements after accelerated aging

An important factor in the long term success of aesthetic restorations is the luting agent which must have properties such as flexural strength and elastic modulus. Purpose: To evaluate the flexural strength and elastic modulus of three commercial resin cements after being submitted to accelerated aging. Materials and methods: Three dual cured resin cements RelyX ARC (3M), Calibra (Densply) and Variolink II (Ivoclar) were used in test as flexural strength and elastic modulus before and after they had undergone an accelerated aging process (300h, UV light, 43±1°C; 50%HR, 18x water spray every two hours). Twenty specimens of each commercial cement (n=60) were prepared according to ISO 4049. The registered values were analyzed statistically using ANOVA and Tukey. Results: The flexural strength of the resin cements increased but with no significant effect (P=0.05). The elastic modulus showed significant differences (P≤0.001), where there was an increment in the values after accelerated aging. Under Scanning Electronic Microscope, there was a superficial degradation in the organic matrix of the dual cured resin cements. Conclusions: Within the limitations of the present study, the dual cured resin cements showed an increment in elastic modulus.