Journal of Dental Research, Vol 76, 1502-1507, Copyright © 1997 by International & American Associations for Dental Research Online Journals
Variability in cytotoxicity and fluoride release of resin-modified glass-ionomer cements
K. C. Kan, L. B. Messer and H. H. Messer
School of Dental Science, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Victoria, Australia.
New-generation glass-ionomer cements contain resin to improve their
restorative properties. These resin-modified glass-ionomer cements vary
considerably in their chemistry, which could result in corresponding
variability in their physical and biological properties. This study
investigated the cytotoxicity and the fluoride release of two
resin-modified glass ionomers, a conventional glass-ionomer cement, and a
resin composite. Samples were prepared and extracted in distilled water for
1, 4, and 7 days; eluates were filtered and tested by means of 3T3 mouse
fibroblasts. Cytotoxicity (MTT assay) values were low for all materials and
extraction times, indicating minimal cytotoxicity of all materials (less
than 30% inhibition). Cytotoxicity of one resin-modified glass ionomer was
significantly higher than for the other materials (p < 0.001). One
resin-modified glass ionomer and the conventional glass-ionomer cement
released significantly more fluoride at each time interval (p < 0.001)
than the other resin-modified glass-ionomer cement and the resin composite.
Fluoride release and cytotoxicity were correlated (r2 = 0.60; p <
0.001), although the fluoride release does not account for the cytotoxicity
observed. Cytotoxicity and fluoride release suggest that one hybrid behaved
more like a conventional glass ionomer, and the other like a resin
composite. These differences may have implications for material selection
in specific clinical situations.
