Objective:To find a simple and effective way to prevent enamel decalcification by guiding patients treated with fixed appliance to brush teeth with fluoride toothpaste.Methods:60 patients treated with fixed appliance were randomly selected and divided into two groups

the fluoride group brushing teeth with fluoride toothpaste

the control group with common toothpaste.The incidence and severity of enamel decalcification in orthodontic treatment either in two groups or in the number of the patient’s teeth of two groups were evaluated before and after treatment.The enamel decalcification index(EDI) was calculated.Results:There was no significant difference either between two groups or the number of the patient’s teeth of two groups before treatment (P>0.05).The incidence of patients of the fluoride group was lower than that of the control group after treatment (P<0.05)

the incidence of teeth of the fluoride group was lower significantly than that of the control group after treatment (P<0.01).The number of teeth whose lesion was 1 score of the fluoride group was higher than that of the control group (P<0.05);the number of teeth which lesions was 3 score of the fluoride group was lower than that of the control group (P<0.05);there was no significant difference between two groups of the teeth which lesions was 2 score (P>0.05);the EDI of the fluoride group was lower than that of the control group (P<0.05).Conclusion:Fluoride toothpaste can effectively prevent enamel decalcification in fixed-orthodontic treatment.