Micro-CT evaluation of laser-fluoride effect on enamel demineralization

Prevention of dental caries has been studied extensively. However, effect of laser and/or fluoride in enamel demineralization remains a challenge until recently due to lack of a non-invasive quantitative tool. Objective: This study aimed to quantify the effect of fluoride and/or Er:YAG laser treatment on enamel demineralization using non-destructive mCT. Materials and Methods: Four windows created on the buccal surfaces of teeth (n=10) were assigned to control (C), laser (L), fluoride (F) and fluoride-laser (F-L) groups. A topical 2% NaF (9047 ppm x 4 minutes) and/or Er:YAG laser (100mJ-5Hz-5seconds) were applied on each assigned window. After a four-day pH-cycling, the average mineral content of enamel was calculated from 3-D grey value intensity measured by mCT scanner. A factorial ANOVA was used to assess the effects and potential interaction of laser and fluoride treatments. Results: Mean mineral loss (%/V) for FL, L, F and C groups are 4869.8(±1434.3), 6340.6(±2203.9), 7668.8(±2255.3) and 10779.3(±2936.0), respectively. Laser (p<0.001) and fluoride treatments (p=0.10) were statistically significant but laser-fluoride interaction was not (p=0.193). The L, F and L-F groups prevent mineral loss around 41%, 29% and 55%, respectively. Conclusion: Er:YAG laser irradiation may provide an effective and additional preventive effect and mCT may be a promising non-invasive tool in quantifying mineral loss in enamel.