The Effects of Gic Restorations on Enamel and Dentin Demineralization and Remineralization

Abstract

Glass-ionomer cement (GIC) restorations release fluoride after placement in the oral environment. This is assumed to be one of the reasons for the decreased prevalence of secondary caries. In the current studies, the effects of GIC restorations on demineralization and remineralization of enamel and dentin lesions were studied, in an in vitro and an intra-oral model, respectively. The in vitro pH-cycling study revealed that the excessive fluoride release of the freshly placed restorations upset the (commonly observed) mineral balance between the specimens and the de/remineralizing solutions. Anomalous patterns of calcium uptake by the specimens (with GIC) during the demineralization phase and calcium loss during the remineralization phase were observed. This was hypothetically explained from the behavior of a surface coating on the GIC restorations, which was observed with SEM. The intra-oral studies showed, after three months in situ, hypermineralization of dentin close to or in contact with the restoration. It is concluded that the fluoride released from GIC or the decreased permeability as a result of hypermineralization causes lower susceptibility of the dentin of the cavity walls.