Clinical evaluations of resin-modified glass-ionomer restorations.

OBJECTIVES: This paper collates some of the existing data on the clinical evaluations of resin-modified glass-ionomer cements (RMGICs) since their introduction two decades ago.
METHODS: The relevant literature was considered and data reviewed under the headings of retention, marginal characteristics, material deterioration, secondary caries, color stability, as well as pulpal and biological effects.
RESULTS: The retention for RMGICs is generally good, with an annual failure rate over 13 years reported as being under 3%. However, more data is required on their performance in carious situations. Regarding marginal characteristics, they exhibit margins that are likely to deteriorate over time. From the limited data on the surface characteristics, they appear to exhibit some wear and loss of anatomic form, particularly in the mid to long term. Despite the fact that the studies reviewed for secondary caries varied in the initial caries status of lesions restored, the overwhelming conclusion is that this does not seem to be a problem. While their initial color match may be favorable, it appears that they change over time and may not be color stable. In the absence of more clinical data, it is difficult to draw conclusions on the pulpal and biological effects. The existing information primarily reports postoperative sensitivity, which fortunately does not seem to be an issue with RMGICs, and limited histopathology of the pulp, with mixed opinions. SIGNIFICANCE: The RMGICs appear to perform well in terms of retention, and secondary caries as well as postoperative sensitivity are not a problem. However, this is not necessarily true of their marginal characteristics, surface properties and color stability. More and long-term clinical research is required to establish compelling evidence of their behavior, particularly in terms of retention in carious cavities, surface properties and biological effects.