CO2 laser and topical fluoride therapy in the control of caries lesions on demineralized primary enamel.

This study evaluated the effect of CO2 laser irradiation and topical fluoride therapy in the control of caries progression on primary teeth enamel. 30 fragments (3 x 3 x 2 mm) from primary canines were submitted to an initial cariogenic challenge that consisted of immersion on demineralizing solution for 3 hours and remineralizing solution for 21 hours for 5 days. Fragments were randomly assigned into three groups (n = 10): L: CO2 laser (lambda = 10.6 mum), APF: 1.23% acidulated phosphate fluoride, and C: no treatment (control). CO2 laser was applied with 0.5 W power and 0.44 J/cm(2) energy density. Fluoride application was performed with 0.1 g for 1 minute. Cariogenic challenge was conducted for 5 days following protocol previously described. Subsurface Knoop microhardness was measured at 30 mum from the edge. Obtained data were subjected to analysis the variance (ANOVA) and Duncan test with significance of 5%. It was found that the L group showed greater control of deciduous enamel demineralization and were similar to those of APF group, while being statistically different from C group (P </= 0.05) that showed the lowest microhardness values. It was concluded that CO2 laser can be an additional resource in caries control progression on primary teeth enamel.