An In Vitro Study to Compare the Release of Fluoride from Glass Ionomer Cement (Fuji IX) and Zirconomer

Mercury toxicity from amalgam dental fillings and their potential for creating problems in the environment and for human health have prompted the development of new restorative materials. The leading alternatives among these are glass ionomer cements. According to current understanding, restorative materials that slowly release fluoride exert a local cariostatic effect. For this purpose, glass ionomer cements have desirable properties in that they help prevent recurrence of caries by releasing fluoride over a long period. Thus, they function in accord with the major cariostatic mechanism of fluoride, which is believed to be its action to promote remineralization and to influence the morphology of teeth by reducing enamel solubility and by suppressing oral cariogenic bacteria. Although the minimum local concentration of fluoride release required to inhibit demineralization has not been determined, it is reported that the cariostatic ability of fluoride releasing restorative materials is significant. Zirconomer defines a new class of restorative that promises the strength and durability of amalgam with the protective benefits of glass ionomer while completely eliminating the hazards of mercury. The inclusion of specially micronized zirconia fillers in the glass component of zirconomer reinforces the structural integrity of the restoration and imparts superior mechanical properties for the restoration of load-bearing permanent teeth. Combination of outstanding strength, durability, and sustained fluoride protection deems it ideal for multiple applications. The aim of the present study was to determine the fluoride release from glass ionomer cements and compare it with new material zirconomer.

Sample preparation: Tablets of glass-ionomer cements and zirconomer were prepared. A dental floss was incorporated into the tablets during fabrication to allow suspension into the test medium. Each disk specimen was immersed in airtight polyethylene bottle containing 20 mL of deionized water and incubated at 37°C and stored for 24 hours.

Fluoride ion measurement was performed after 6 hours, 24 hours, 48 hours, 7 days, and 14 days under normal atmospheric conditions by fluoride ion selective electrode connected to an ion selective electrode meter.

Both the material tested in the study had the ability to release fluoride but higher fluoride release was observed by zirconomer as compared to GIC at all time intervals.

From a clinical point of view, both the restorative materials release fluoride at all time intervals; however, addition of zirconia particles in zirconomer increases its strength and provides superior mechanical properties. Therefore, due to the combination of both good structural integrity and fluoride releasing properties, zirconomer can be used for restoration of load bearing teeth.

Kukreja R, Singla S, Bhadoria N, et al. An In Vitro Study to Compare the Release of Fluoride from Glass Ionomer Cement (Fuji IX) and Zirconomer. Int J Clin Pediatr Dent 2022;15(1):35-37.