effect of CPP-ACP paste on shear bond strength of glass ionomer to dentine

ABSTRACT

CPP-ACP is one of the numerous materials which is used in dental hypersensitivity and works through changing Cagradient in tooth surface, besides glass ionomer is a selective material in restoring non -carious cervical lesions because of chemical bonding. In this study we evaluate the effect of CPP-ACO on shear bond strength of glass ionomer to dentine. In this experimental study, 40 third molar teeth were sectioned to obtain dentine with tubule orientation perpendicular to the surface. The specimens were divided into 4 groups [A to D].Groups A and B were treated with CPP-ACP paste for 60 min x 5 days. Groups A and C were treated with polyacrylic acid 10% for 20 min before glass ionomer adhesion. All specimens were bonded with glass ionomer. After 24 +/- 1 hours water storage, the bonded specimens were sectioned with universal testing machine. There was no significant effect in shear bond strength to dentine in groups except groups B.There was no significant effect in failaure pattern. Most of the failure patterns were adhesive mode. CPP-ACP application in dentine surface reduces the shear bond strength of glass ionomer except the preconditioning of dentine with polyacrylic acid 10%. Preconditioning in dentine surface nontreated with CPP-ACP paste, does not affect the shear bond strength of glass ionomer