Clinical performance of glass-ionomers.

Glass-ionomers were introduced to the profession 20 years ago and have been shown to be a very useful adjunct to restorative dentistry. Their major advantages include the ion exchange adhesion to both enamel and dentine and a continuing fluoride release throughout the life of the restoration. The chemistry of the setting reaction is essentially an acid/base reaction but recent research has introduced variations in an effort to improve clinical handling. Small additions of resin increase the physical properties to a degree and allow for a light-initiated setting mechanism. However, it is essential that the acid/base reaction remains dominant if the full advantages of the glass-ionomer are to be retained. The material has multiple uses in dentistry and it shows a high degree of biocompatibility to the pulp and surrounding soft tissues. The main limitation at this time is a relatively low fracture resistance but it is possible to protect it through lamination with stronger materials if the need arises. This paper examines the essential parameters for successful clinical placement and comments on its longevity.