Abstract
BACKGROUND: Dental erosion and abrasion lead to progressive enamel loss, and preventive strategies often rely on fluoride dentifrices. Bioactive silica has emerged as a promising component due to its remineralizing potential, acting alone or synergistically with fluoride. This in vitro study evaluated the efficacy of bioactive silica dentifrices, with or without different fluoride concentrations, in promoting enamel remineralization and protecting against erosion‒abrasion cycles. METHODS: Sixty bovine enamel samples were assigned to five groups: RGS1 (bioactive silica dentifrice with 1450 ppm F), RGS2 (bioactive silica dentifrice with 1100 ppm F), RGS3 (bioactive silica dentifrice without fluoride), positive control (PC, 1100 ppm F dentifrice), and negative control (NC, fluoride- and silica-free dentifrice). The samples were subjected to a 5-day erosion-abrasion cycle with daily treatment with the assigned dentifrices. Enamel changes were assessed through surface microhardness recovery (%SMHR), fluorescence recovery (%ΔFR), surface loss (ΔSL), and surface roughness variation (ΔRa). The data were analyzed via one-way and repeated-measures ANOVA, followed by Tukey's post hoc test (α = 0.05). RESULTS: All tested dentifrices significantly affected enamel properties. Compared with the controls, bioactive silica dentifrices improved the microhardness and promoted greater mineral gain (p < 0.05). RGS2 demonstrated the highest %SMHR and ΔFR values, along with lowest surface roughness and enamel loss, indicating superior protective potential. RGS1, RGS3 and PC followed, with intermediate outcomes. The NC group exhibited the poorest performance across all the parameters evaluated (p < 0.05). CONCLUSION: Bioactive silica dentifrices significantly enhance enamel remineralization and protection against erosion-abrasion. The results highlight both the synergistic and independent roles of bioactive silica, supporting its application in daily oral care strategies for managing enamel wear. CLINICAL TRIAL NUMBER: Not applicable.