CO 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.

Objective: This in situ study aimed to investigate the efficacy of CO 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 CO laser irradiation and APF alone or combined with FD. Treatment groups were non-fluoridated dentifrice-NFD, NFD + CO laser, NFD + APF, NFD + CO laser + APF, FD, FD + CO laser, FD + APF, and FD + CO laser + APF. Mineral loss, calcium fluoride (CaF), 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 CO laser irradiation were combined, which did not significantly differ from the FD + CO laser + APF group. The CaF, FAp, and F in the biofilm were more pronounced when the FD and APF were combined. The CO laser irradiation promoted a slightly higher concentration of CaF in the enamel and F in the biofilm.

Conclusion: Although APF promotes the high formation of CaF and FAp, the combined use of FD with CO 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 CO laser irradiation and daily use of fluoridated dentifrice. Future clinical trials are encouraged to substantiate this finding.