Effect of polyacrylic acid pretreatment on the microtensile bond strength of self-adhesive resin cement and resin modified glass ionomer cement to dentin

Abstract

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.