Potential of CO₂ lasers (10.6 µm) associated with fluorides in inhibiting human enamel erosion

This in vitro study aimed to investigate the potential of CO₂ lasers associated with different fluoride agents in inhibiting enamel erosion. Human enamel samples were randomly divided into 9 groups (n = 12): G1-eroded enamel; G2-APF gel; G3-AmF/NaF gel; G4-AmF/SnF₂ solution; G5-CO₂ laser (λ = 10.6 µm)+APF gel; G6-CO₂ laser+AmF/NaF gel; G7-CO₂laser+AmF/SnF₂solution; G8-CO₂ laser; and G9-sound enamel. The CO₂ laser parameters were: 0.45 J/cm²; 6 μs; and 128 Hz. After surface treatment, the samples (except from G9) were immersed in 1% citric acid (pH 4.0, 3 min). Surface microhardness was measured at baseline and after surface softening. The data were statistically analyzed by one-way ANOVA and Tukey’s tests (p < 0.05). G2 (407.6 ± 37.3) presented the highest mean SMH after softening, followed by G3 (407.5 ± 29.8) and G5 (399.7 ± 32.9). Within the fluoride-treated groups, G4 (309.0 ± 24.4) had a significantly lower mean SMH than G3 and G2, which were statistically similar to each other. AmF/NaF and APF application showed potential to protect and control erosion progression in dental enamel, and CO₂ laser irradiation at 0.45J/cm² did not influence its efficacy. CO₂ laser irradiation alone under the same conditions could also significantly decrease enamel erosive mineral loss, although at lower levels.

Dental Enamel; Fluorides; Lasers; Hardness; Tooth Erosion