Glass ionomer cements and future research.

Once a root surface lesion has extended into tooth structure beyond the point at which it can be successfully remineralized it is necessary to carry out traditional restorative procedures. Often the extent of the lesion is difficult to define and development of a pulp exposure is an ever present risk. Access may be difficult and placement of a restorative material, such as amalgam, which requires positive condensation for correct placement, poses a problem. The principal requirement of a restoration in such a lesion is that it should completely seal the restoration/tooth interface and prevent the ingress of further bacteria or bacterial nutrients. As there will be no occlusal load, physical properties of the restorative material are not significant. As these lesions will often occur on anterior teeth it is desirable that the material be reasonably esthetic although there will be no need for a great depth of translucency. The modern trend to light curing of restorative materials facilitates placement but there are situations with these lesions where it is difficult or impossible to obtain proper access for the light and an auto cure material may be indicated. Because the patient who presents with root surface lesions is likely to pose a continuing problem, it is desirable that the restorative material have some degree of in-built protection against further demineralization. An ongoing fluoride release is very desirable. Glass ionomer cement fulfils all the above requirements and is therefore at present the material of choice. Either the original auto cure cement or the newer dual cure materials will provide a complete marginal seal with a continuing fluoride release throughout the life of the restoration and both varieties are sufficiently esthetic to be entirely acceptable.