Non metallic restorative materials based on glass ionomer cements - recenttrends and developments

In this contribution to a series of papers dealing with the colloid chemist ry and structure of restorative and luting material for dentistry we will p resent a short introduction into the state-of-the-art of applying and devel oping dental material based on glass ionomer cement (GIC). The basic compon ent of glass of GIC and related material is a glass-like calcium aluminosil icate containing some fluoride and an acidic polyelectrolyte, which is a ho mopolymer or copolymer of unsaturated carboxylic acids. The glass-ionomer c ement sets as a result of a reaction between an acid and a base. The produc t of the reaction, a hydrogel salt, acts as a binding matrix surrounding th e silicate particles. More recently, resin modified systems have become ava ilable commercially. These materials have dual-curing capabilities. The aci d-base reaction is initiated on mixing, but proceeds slowly and thus the ov erall setting is accelerated by a light-activated polymerization mechanism. The major advance in the glass ionomer cement is its ability to adsorb per manently to the hydrophilic surface of tooth hard substance. The bond stren gth with glass ionomer cements may be enhanced by cleaning organic debris o ff dentin and enamel surfaces with polyacrylic acid. Another advantage of g lass ionomers is constant fluoride release, which inhibits secondary caries . (C) 2000 Elsevier Science B.V. All rights reserved.