Diode Laser irradiation and fluoride uptake in human teeth

AIM: To evaluate chemically the effects of diode laser onfluoride uptake before and after laser irradiation of enamelsurfaces. METHODS: Crowns of 20 sound human teethwere halved and a 3x3mm acid-resistant varnish uncoveredwindow left for: A) no treatment; B) fluoride (Elmexgel); C) diode (fluoride + diode laser); D) diode (diodelaser + fluoride). The dental surfaces were analysed usinga fluoride ion-selective electrode, in order to evaluatethe fluoride treatment in combination with a diode laser.Also, to investigate laser-induced compositional changes(contents in F-) in enamel before/after laser irradiation andtopical fluoride application. RESULTS: The mean ±SD offluoride uptake of teeth of group A was 1.55 ± 0.89 mg/l.Mean fluoride uptake increased sevenfold after fluoridegel treatment: 10.51 ± 3.38 mg/l for group B, up to 15times after gel and laser treatment: 23.62 ± 3.58 mg/lfor group C and was 22.7 ± 4.60 mg/l for group D (diodelaser before fluoride application). The Kruskal Wallis testindicated a statistically significant effect of fluoride uptakefor all three treatments (p<0.001). The Student-Newman-Keuls multiple comparison test indicated a statisticallysignificant increase of fluoride uptake before and after alltreatments, and also a statistically significant difference forlaser treatment versus fluoride gel. However, there was nostatistically significance difference between laser groups.CONCLUSIONS: There is an enhanced capability oflasers to increase fluoride uptake of enamel and providingprotection to enamel surface from acid attack.