@Article{, title={The effect of ER: YAG laser on enamel resistance to caries during orthodontic treatment: An in vitro study}, author={Noor M.H. Garma نور محمد حسن and Esraa S. Jasim}, journal={Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد}, volume={27}, number={1}, pages={182-188}, year={2015}, abstract={Background: One common undesirable side effect of orthodontic treatment with fixed appliances is thedevelopment of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Differentmethods have been used to prevent demineralization; the recent effort to improve the resistance against thedemineralization is by the application of lasers.Materials and method: Thirty human premolars extracted for orthodontic purposes were used to test the effect of twoenergy level of ER-YAG laser on enamel resistance to demineralization. The brackets were bonded on the teeth andall the labial surface excluding 2 mm area gingival to the brackets were painted with acid resistance varnish. Threegroups were generated. The first group was the control group (A) with no treatment was performed. In the second(group B) and third (group C) groups; teeth were irradiated by ER-YAG laser of 200, 60 mj energy respectively. All theteeth were individually subjected to acid challenge cycle for 30 days. After debonding longitudinal sections weretaken and examined under stereomicroscope. The enamel demineralization evaluation was done by taking theaverage of three depths at the centre of the artificial lesion. Also the enamel surface was classified by anexperienced investigator according to acid etch pattern. Comparisons of the average depth values of the groupswere performed with ANOVA and LSD tests. The statistical significance level was set at p ≤ 0.05.Results: The results revealed that average lesion depth was significantly deeper at the control group than the lasergroups, and it was significantly deeper in group (B) with 200 mj than in group (C) with 60 mj. Enamel surfaces showeddeeper pits and craters than in control group.Conclusions: The decrease in artificial caries lesion depth associated with use of the two laser energy level supportthe ER-YAG laser as a tool to increase enamel resistance to demineralization and white spot lesion prevention

} }