The effects of combining erbium, chromium: Yttrium-scandium-gallium-garnet laser irradiation with fluoride application in controlling the progression of enamel erosion

Highlights • Fluoride alone increased the microhardness of the enamel surface. • Fluoride alone halted the progression of enamel erosion. • Laser irradiation before fluoride-induced similar effects as fluoride alone. • Laser irradiation alone did not prevent the progression of enamel erosion.
Objective Increasing enamel resistance to acid may be useful for preventing cavitation and could reduce changes in the enamel’s microhardness. Topical fluoride application and laser irradiation promote acid resistance of dental substrates. The aim of the study was to assess the efficacy of erbium, chromium: yttrium-scandium-gallium-garnet laser irradiation in combination with fluoride application to control enamel erosion. Design Sixty human premolar specimens were prepared (N = 60) and were randomly assigned to 5 groups, twelve specimens in each group (n = 12/group) according to surface treatment. The groups were as follows: group 1 (C): control with no treatment; group 2 (F): application of 1.23% acidulated phosphate fluoride gel alone; group 3 (L): laser irradiation alone; group 4 (F+L): acidulated phosphate fluoride gel followed by laser irradiation; group 5 (L+F): laser irradiation followed by acidulated phosphate fluoride gel. All the specimens were eroded 10 min in citric acid. Baseline measurements were performed using a Vickers microhardness tester before surface treatment. Subsequently, all specimens were subjected to a 60 min erosion-remineralization cycle for five days followed by measurements of the final surface microhardness. Statistical comparisons were performed by a one-way analysis of variance and Tukey’s post hoc analysis. Results The control, laser, and fluoride + laser groups showed a statistically significant decrease in microhardness values between baseline and post-erosion measurements (P