A study investigated the combined effect of fractional CO2 laser irradiation and fluoride on treatment of enamel caries. The study involved 60 intact premolars which were randomly assigned into 4 groups, followed by storage in a demineralizing solution to induce white spot lesions. Tooth color was determined at baseline (T1) and after demineralization (T2). Teeth in group 1 remained untreated (control); group 2 was exposed to an acidulated phosphate fluoride (APF) gel for 4 minutes; group 3 received a fractional CO2 laser application (10 mJ, 200 Hz, 10 s) before the APF gel; group 4 received a fractional CO2 application through the APF gel. The teeth were then immersed in artificial saliva for 90 days while subjected to daily fluoride mouthrinse and weekly brushing. Color examinations were repeated after topical fluoride application (T3) and 90 days later (T4). The teeth were then sectioned, and microhardness was measured at the enamel surface and at 30 μm and 60 μm from the surface. The study found that in both lased groups, the color change between T1 and T4 stages (∆ET1-T4) was significantly lower than those of the other groups (P < .05). Laser irradiation followed by fluoride application (group 3) caused a significant increase in surface microhardness compared to APF alone and control groups (P < .05). Microhardness at depths of 30 and 60 μm was also significantly greater in group 3 compared to those of all other groups (P < .05). The study authors Dr. Poosti et al conclude that application of a fractional CO2 laser before fluoride therapy is suggested for recovering the color and rehardening of demineralized enamel.
(Source: Lasers in Medical Science, March 2013)
