
Glass ionomers were introduced to the profession 25 years ago and have been shown to be a very useful adjunct to restorative dentistry. Glass ionomer cement composed of a calcium – alumino – silicate glass powder and an aqueous solution of an acrylic acid homo – or copolymer. These cements possess certain unique properties that make them useful as restorative and adhesive materials, including adhesion to tooth structure and base metals, anticariogenic properties due to release of fluoride, thermal compatibility with tooth enamel, and biocompatibility.