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

Abstract

Objectives 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. Methods 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. Results 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. Significance 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.