Aim of the study: to evaluate in vitro the effect of dentin surface pretreatment with polyacrylic acid on the microtensile bond strength (µTBS) of self-adhesive resin cements and resin modified glass ionomer luting cements (RMGIC).
Materials and Methods: The occlusal enamel of 16 teeth was removed perpendicular to the long axis of teeth to expose flat dentin surface at a standardized depth which is 1mm apical to DEJ. The teeth were randomly divided into 4 groups according to cementation protocol of indirect resin composite blocks namely; RelyX-Unicem with no pretreatment, RelyX-Unicem with polyacrylic acid pretreatment, FujiCEM (RMGIC) with no pretreatment and FujiCEM (RMGIC) with polyacrylic acid pretreatment. The restored teeth were mounted on the cutting machine, sectioned into a series of 1 mm2 thick. The sticks were stressed to failure under tension using Universal Testing Machine to record the microtensile bond strength. The collected data were submitted to ANOVA and Tukey's test.
Results: The highest mean value was detected in RelyX-Unicem with no pretreatment, followed by Fujicem with polyacrylic acid pretreatment; whereas the lowest value was recorded in Fujicem with no pretreatment. Using two ways ANOVA revealed that material type had a statistically significant effect (p=0.003), with a higher mean value in RelyX-Unicem. However, pretreatment had a non-significant effect (p=0.510). The interaction of the two variables had a statistically significant effect (p<0.0001).
Conclusion: Polyacrylic acid adversely affects the microtensile bond strength of self-adhesive resin cement; however it improves bond strength of RMGIC.