Glass Ionomer Cements: A Review of Composition, Chemistry, and Biocompatibility as a Dental and Medical Implant Material

Glass ionomer cements are a group of materials based on the acid/base reaction between poly(alkenoic) acid and an ion-leachable silicate glass. The material was developed in dentistry as a tooth restorative material that released fluoride ions over an extended time, bonded to tooth structure, and was very biocompatible. Its use in dentistry was initially limited by its slow setting time and lack of strength; however, modern formulations of the material have yielded materials with properties that are clinically useful in dentistry. Its biocompatibility, osteoconductive behavior, and ability to bond to bone and metals have generated interest in the material for medical applications. Glass ionomer cements in medicine have been used as bone cements, implants to replace ossicular bones of the inner ear, as well as other craniofacial implants. The early release of fluoride and aluminum ions and release of polyacids have been implicated in tissue biocompatibility in medical use. Additional material development is necessary to optimize its properties for use in medicine. This article reviews the literature written on the composition, chemistry, fluoride release, biocompatibility, and medical uses of glass ionomer cements.