CO2 laser irradiation combined with fluoridated dentifrice improved its protective effect on caries lesion progression regardless of the acidulated phosphate fluoride gel application: An in situ study

Abstract

Objective: This in situ study aimed to investigate the efficacy of CO₂ laser at a 10.6-µm wavelength combined with 1.23% acidulated phosphate fluoride (APF) and fluoridated dentifrice with 1100 µg F/g (FD) to control enamel caries progression.

Materials and methods: Sixteen volunteers wore palatal appliances containing eight demineralized enamel specimens for four 14-day phases under sucrose exposure. These specimens were submitted to CO₂ laser irradiation and APF alone or combined with FD. Treatment groups were non-fluoridated dentifrice-NFD, NFD + CO₂ laser, NFD + APF, NFD + CO₂ laser + APF, FD, FD + CO₂ laser, FD + APF, and FD + CO₂ laser + APF. Mineral loss, calcium fluoride (CaF₂), fluorapatite (FAp), and fluoride in the biofilm were analyzed by analysis of variance followed by the Student-Newman-Keuls test, p < 0.05.

Results: The highest mineral loss inhibition was noted when FD and CO₂ laser irradiation were combined, which did not significantly differ from the FD + CO₂ laser + APF group. The CaF₂, FAp, and F in the biofilm were more pronounced when the FD and APF were combined. The CO₂ laser irradiation promoted a slightly higher concentration of CaF₂ in the enamel and F in the biofilm.

Conclusion: Although APF promotes the high formation of CaF₂ and FAp, the combined use of FD with CO₂ laser overcomes the APF effect in inhibiting the progression of artificial caries-like lesions in situ.

Clinical significance: Under the in situ design of this study, remineralization of white spot lesions was achieved through CO₂ laser irradiation and daily use of fluoridated dentifrice. Future clinical trials are encouraged to substantiate this finding.

Keywords: CO2 laser; Dental caries; Enamel; Fluoride.