A review of powder modifications in conventional glass-ionomer dental cements

Glass-ionomer dental cements (GICs) have proven to be useful in several areas of dentistry such as restorative dentistry. Glass-ionomers are aqueous cements formed by the reaction of an acidic polymer and a basic glass in the presence of water. The oral environment presents many challenges to the longevity of restorative materials. Glass-ionomer cements have many properties that are clinically useful and promote longevity. Importantly, GICs adhere to moist tooth structure without any pretreatment, and provide a prolonged period of fluoride release, which inhibits recurrent tooth decay (caries). These properties together with acceptable aesthetics and biocompatibility make these materials popular and desirable for medical and dental applications. However, glass-ionomer dental cements have limitations that prevent broader clinical adaptation such as poor mechanical properties and moisture sensitivity. Many significant changes and modifications to the chemistry of the acidic polymers and basic glasses and to the formulation of the cements have been made to address these limitations. In this review, advances in the development of the basic glasses and other reinforcing agents will be discussed. An overview of the chemistry of glass-ionomer cements will be discussed followed by an in-depth discussion of the chemistry of novel basic glasses and reinforcing additives.