ENHANCEMENT OF FLUORIDE-INDUCED REPAIR OF NON-CAVITATED ENAMEL CARIES LESION BY CO-DELIVERY OF SILVER IONS AND IRRADIATION BY LOW-ENERGY LASERS

Abstract

Topical fluorides (F), suggested to play key role in caries control, results in surface deposition of crystalline F with inadequate amounts of critical loosely-bound F (F reservoirs) in caries lesion, limiting its cariostatic effect. Hence, this study aimed to determine if co-delivery of silver (Ag) and F ions, with/without lasers, would synergistically enhance F effectiveness in treating enamel caries. The findings showed Ag+F treatment partially blocked crystalline F incorporation due to Ag-altered crystal morphology, potentially resulting in more F reservoirs in the lesion, leading to greater inhibition of lesion progression after Ag+F treatment, compared to F treatment. Secondly, Ag treatment resulted in significant reductions in enamel diffusion rates by deposition of crystal-bound silver precipitates in diffusion pathways. Thirdly, combined laser-fluoride treatment resulted in greater reductions in porosity and %mineral loss, compared to F treatment. These novel mechanism(s) may aid to enhance clinical effectiveness of F-based therapies in caries control.