Comparative Evaluation of the Remineralizing Effects and Surface Microhardness of Glass Ionomer Cements

Glass ionomer cements (GICs) are widely used in restorative dentistry.1 In dentistry, one of their advantages over other restorative materials is that they can be placed into tooth cavities without an additional bonding agent.2 They also possess a fluoride-releasing property3 and are relatively biocompatible with the pulp.1 Adhesive property and fluoride release of glass ionomer cement contribute to reduce the rate of secondary caries both in filled teeth and on the enamel surfaces of adjacent teeth.4,5 Although, widely used as dental cements, GICs have some disadvantages. One problem is that they do not always bond sufficiently to enamel and dentin. The mechanical strength decreased significantly when the paste is exposed to saliva at the initial stage of setting. To overcome this drawback, conventional glass ionomer cement was modified by water soluble resin.6 These resin modified glass ionomer cements (RMGICs) provided improved mechanical properties and adhesion, better esthetics, easier application with reduced moisture sensitivity and immediate light cure after placement.7 They were mostly found to have a potential for releasing fluoride in equivalent amounts as conventional glass ionomer cements.8 Bioactive glasses (BAG) are surface-active glasses with which bone minerals are able to bond chemically.9 The components in bioactive glass are basically oxides of calcium, sodium, phosphorus, and silicon at certain weight Abstract