Assessment of Enamel Demineralization Resistance and Shear Peel Bond Strength of Protein Repellent Orthodontic Glass Ionomer Cement

Abstract

Objective: The purpose of this work was to create a novel orthodontic glass ionomer cement (GIC) modified with a protein repellent substance to resist enamel demineralization without compromising the bond strength.Materials and Methods. 2-Methacryloyloxyethyl phosphorylcholine (MPC) was incorporated into the GIC at 0,1.5, 3, 5 wt. Teeth were bonded to stainless steel bands then immersed in demineralizing media. Bands were removed then teeth were sectioned. Surface morphology, Ca and P wt% were evaluated utilizing the scanning electron microscopy combined with energy dispersive X-ray spectroscopy. Shear peel bond strength (SPBS) assessed using a universal testing machine. The adhesive remnant index (ARI) was employed. The data were statistically analyzed by one-way ANOVA. Chi square test was used to compare between groups for ARI.Results: Ca and P wt% was significantly increased with increasing MPC ratio. Pores and cracks on enamel surface were significantly decreased with 1.5, 3 wt % MPC, 5 wt% MPC showed glossy enamel surface with absence of cracks and porosity. SPBS of 1.5, 3 wt % MPC powder showed non-significant change compared to the control group, while there was significant decrease for 5 wt% MPC modified GIC.Conclusions: Adding 3 wt% MPC into GIC used for cementation of orthodontic band is efficient for the resistance of enamel demineralization without any significant influence on the shear peel bond strength.