The Cariostatic Effect of Glass Ionomers with Varying Fluoride Quantities

Recurrent marginal decay continues to be a problem affecting the longevity of restorations. Resin modified glass ionomers have been proven to be cariostatic against secondary root caries. Objective: The purpose of this study was to assess the cariostatic effects of two glass ionomer products with varying fluoride content; Fuji IX GP EXTRA and Fuji IX GP FAST. Methods: Forty extracted sound human molars were selected and randomly assigned to four material groups: amalgam with no fluoride; Heliomolar, a composite fluoride; Fuji IX GP FAST and Fuji IX GP EXTRA. Standardized Class V cavity preparations 2mm by 5mm were made at the CEJ and restorations placed. An acid-resistant varnish was applied to the teeth excluding a 1mm margin surrounding the restoration. The teeth were immersed in a demineralization solution at pH 4.40 for 72hrs. Each tooth was sectioned and polarized light microscopy was used to measure the demineralization at the restoration-tooth interface (wall lesion) and outer lesion. Data was analyzed by ANOVA and Tukey's post test (á<0.05). Results: The Heliomolar composite group had significantly smaller outer lesion depth (p<0.05) than the Fuji IX GP FAST glass ionomer. The amalgam group had the greatest wall lesion depth and both Fuji IX Extra and Fuji IX GP FAST exhibited significantly smaller (p<0.01) wall lesion depths when compared to amalgam, but only Fuji IX GP Extra group demonstrated a significantly smaller (p<0.01) wall lesion depth than the Heliomolar group. Conclusions: The Fuji IX glass ionomers had no effect on outer lesion depth; however both products provided substantial reduction in wall lesion depth. When the Fuji IX GP Extra and Fuji IX GP FAST were compared, no significant differences were observed indicating that although the Fuji IX GP Extra contained more fluoride, it did not provide a greater zone of inhibition at the interface.