Effect of CPP-ACP addition on physical properties of zinc oxide non-eugenol temporary cements

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) is a milk derivative which holds nanoclusters of calcium and phosphate ions. The presence of CPP-ACP has been found to reduce demineralization and enhance remineralization in subsurface enamel and in dentin. Incorporation of CPP-ACP into luting cements has not been investigated. The aim of this study was to determine the effect on the physical properties of two commercially available zinc oxide non-eugenol temporary luting cements with incorporation of up to 8% (w/w) CPP-ACP.

Setting time, compressive strength, diametral tensile strength, film thickness and solubility tests were investigated for 0, 0.5, 1.0, 2.0, 3.0, 4.0 and 8.0% (w/w) CPP-ACP incorporated into Freegenol™ and Temp-Bond(®) NE. Tests were carried out based on ISO 3107 requirements.

Compressive and diametral tensile strengths progressively decreased with increasing concentrations of up to 8.0% (w/w) CPP-ACP incorporated into both Freegenol™ and Temp-Bond(®) NE. Setting time was delayed beyond ISO requirements. Film thickness was not adversely affected. Increased solubility of Temp-Bond(®) NE with 8.0% (w/w) CPP-ACP incorporation suggested an effect of the CPP-ACP on this property for this cement.

The incorporation of up to 8.0% (w/w) CPP-ACP into two zinc oxide non-eugenol luting cements has no adverse effects on the film thickness, compressive strength and diametral tensile strength of the cements investigated. Solubility investigations suggest that CPP-ACP leaches out of the zinc oxide non-eugenol luting cements into an aqueous environment.