effect of diode laser irradiation combined with topical fluoride on enamel microhardness of primary teeth.

laser irradiation has been suggested as an adjunct to traditional caries prevention methods. but little is known about the cariostatic effect of diode laser and most studies available are on permanent teeth.the purpose of the present study was to investigate the effect of diode laser irradiation combined with topical fluoride on enamel surface microhardness.forty-five primary teeth were used in this in vitro study. the teeth were sectioned to produce 90 slabs. the baseline vickers microhardness number of each enamel surface was determined. the samples were randomly divided into 3 groups. group 1: 5% naf varnish, group 2: naf varnish+ diode laser at 5 w power and group 3: naf varnish+ diode laser at 7 w power. then, the final microhardness number of each surface was again determined. the data were statistically analyzed by repeated measures anova at 0.05 level of significance.in all 3 groups, microhardness number increased significantly after surface treatment (p 0.05).the combined application of diode laser and topical fluoride varnish on enamel surface did not show any significant additional effect on enamel resistance to caries.