Objective To investigate the preventive effectiveness in reducing tooth decay and decalcification of different concentration of fluoride toothpaste for orthodontic patients. Methods 86 patients were divided into the first test group and the second test group. The patients of the first test group brushed tooth with 1.1% sodium fluoride and acidulated phosphate gel. The patients of the second test group brushed tooth with 0.243% sodium fluoride in a silica base. The extent of facial tooth decay and decalcification of the twelve upper and lower teeth from right cuspid to left cuspid was scored blindly and independently by four observers after 12 months of product use. The scores were rated either one（having tooth cavity/decalcification） or zero（no tooth cavity/decalcification）. Four observer's readings were averaged per tooth, and then per patient for the two treatment groups. Results After 12 months of product use, the mean caries score of the first test group was 0.326, and the mean caries score of the second test group was 0.490. There was significant difference between them. Conclusion A gel system containing 1.1% sodium fluoride and acidulated phosphate provides a clinically better efficacy in reducing tooth decay and decalcification than does a toothpaste containing 0.243% sodium fluoride in a silica base under and adjacent to orthodontic brackets used in orthodontic therapy.
