Graphene oxide-modified fluoridated varnish promotes mineral recovery in demineralized bovine enamel: An in vitro study.

Abstract

This in vitro study evaluated the efficacy of an experimental fluoridated varnish modified with graphene oxide (GO) nanoparticles in arresting initial caries lesion progression and promoting mineral recovery in demineralized bovine enamel. Enamel blocks (6 × 4 × 2 mm) were artificially demineralized and treated with one of five varnish formulations: CTRL (experimental varnish), 10% GO (CTRL + 10% GO), 20% GO (CTRL + 20% GO), NaF/CaF₂ (CTRL + NaF + CaF₂), or NaF (Duraphat; Colgate-Palmolive). Following varnish application, specimens were stored in artificial saliva (37°C, 24 h) and subjected to a 7-d pH-cycling regimen. Surface hardness outcomes (%SHL, %SHR, and ΔSH) were determined using six specimens per group. Additional specimens were prepared for transverse microradiography (n = 3 per group) to determine integrated mineral loss (ΔZ) and lesion depth was measured, and the specimens were examined using field-emission scanning electron microscopy (FEG-SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). (n = 9 per group) to evaluate surface morphology, Ca, P, and the Ca/P ratio. Data were analyzed using appropriate parametric or non-parametric tests (α = 0.05). Overall, the 10% GO group exhibited significantly lower %SHL and higher %SHR than the other experimental groups, whereas higher Ca/P ratios were observed in the 10% GO and NaF groups.