Fluoride Release and Inhibition of Caries Around Restoration by Ion Releasing Restorative Materials: An In Vitro Study

Abstract

Objectives: To evaluate and compare fluoride release of three ion releasing restorative materials and assess their inhibitory effect on secondary caries induced by cariogenic bacteria. Materials and Methods: Three ion releasing restorative materials, self-adhesive hybrid composite (group A), ion releasing flowable composite liner (group B), and alkasite restorative material (group C), were examined. Twenty-two discs were fabricated from each material for fluoride release test, conducted on days 1, 7, and 14. For assessing secondary caries inhibition, sixty-six sound molar teeth were used and standardized class V cavities were prepared. Teeth were divided into three groups according to each material, followed by 2000 cycles of thermocycling. Subsequently, teeth were immersed in a solution containing cariogenic bacteria for 30 days. After that, teeth were sectioned bucco-lingually and analyzed using a polarized light microscope to measure inhibition area, outer lesion depth, and extension. Data was statistically analyzed using different tests. Results: Statistically significant differences in fluoride release existed among materials. Self-adhesive hybrid composite exhibited the highest fluoride release, followed by alkasite restorative material and ion releasing flowable composite liner. Lesion extension and depth were statistically significantly greater next to ion releasing flowable composite liner, while next to alkasite restorative material, they exceeded those next to Self-adhesive hybrid composite. The inhibition areas next to self-adhesive hybrid composite were statistically significantly larger than alkasite restorative material and ion releasing flowable composite liner. Conclusion: All three ion releasing restorative materials displayed fluoride release and potential to inhibit secondary caries formation. Self-adhesive hybrid composite demonstrated the highest fluoride-releasing potential and the greatest ability to inhibit secondary caries. Conversely, ion releasing flowable composite liner exhibited the least fluoride release with minimal secondary caries inhibition. Increasing fluoride release correlated with larger inhibition areas and reduced outer lesion depth and extension.