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

Abstract

Glass-ionomer dental restorative cements have proven to be quite practical in different areas of dentistry. An aqueous polyelectrolyte system, glass-ionomer cements have exceptional properties such as a prolonged period of fluoride release which inhibits recurrent caries, adhesion to moist tooth structure without any pretreatment, satisfactory aesthetics and biocompatibility. This makes these cements very popular and attractive for restorative dentistry and also for orthopedics. However, they have some disadvantages such as poor mechanical strength and moisture sensitivity in the early stages of setting. Lately there have been significant modifications in the formulation of the powder and liquid of the glass-ionomer cements, leading to improved mechanical and handling properties of the material. This paper is the second paper of its series, which reviews the modifications to the polymeric component of glass-ionomer dental cements. In this manuscript, the poly(acrylic acid) (PAA) based polymers currently used in glass-ionomer cements are reviewed. Different methods of reinforcement of the glass-ionomer cements by modification of the polymeric liquid; including new acrylic acid copolymers, amino acid containing polyelectrolyte, N-vinylpyrrolidone and N-vinylcaprolactam modified terpolymers are described. The paper discusses the advantages and disadvantages of different modifications and illustrates the future aspects of the materials chemistry.