Expression Of BMP-2 In Periodontal Tissues During Orthodontic Tooth Movement In An Animal Experimental Study

OBJECTIVE:BMP-2 is the bone morphogenetic proteins (BMPs) superfamily member, BMP-2 has the highest osteogenic activity, can cross-species induction of undifferentiated mesenchymal stem cells into bone cells in the direction of proliferation and differentiation and promote bone formation, and the most importantly, one of extracellular signal molecules. The main purpose of this study the expression of BMP-2 in periodontal tissues during Orthodontic tooth movement in rat.METHOD:Select whose weights 200±20 g, the 8 weeks old SD (Sprague Dawley) male rats.The total number was 18, three as a group, were randomly divided into 6 groups. According to the classical cycle of orthodontic,we set up for the 1 day group,3 days group,5 days group,7 days group,14 days group,21 days group. Establishing the orthodontic tooth movement model in SD rat oral. The experimental side of the left maxillary arch, the right to control side. A coil spring was placed between the maxillary first molar and the maxillary central incisors, the central incisors are the anchorage teeth.The first molar was moved to the mesial by 40g force. In accordance with the experimental group were the 1,3,5,7,14,21 days in the experimental perfusion rats were killed and specimens were internal and external fixation. HE conventional histological staining,using streptomycin avidin-biotin complex (SABC) immunohisto-chemical chemical method to detect rats during orthodontic tooth movement in BMP-2 in periodontal tissue expression. PBS instead of primary antibody as negative control. Analysis software with spps13.0 gray value of the measured and analyzed statistically. RESULTS:BMP-2 in the existence of various periods of orthodontic tooth has a specific distribution patterns. The results show that the experimental group in the tension side of periodontal ligament BMP-2 was higher than the pressure side. Orthodontic tooth movement of the bone remodeling process of BMP-2 levels increased with time was first increased and then decreased trend. Experimental side, the expression of BMP-2 in the first 5 days to reach the peak, the first 21 days of near-normal levels of the control group.CONCLUSION:In the tension side of the periodontal membrane and alveolar bone osteoblasts and fibroblasts positive expression of BMP-2 shows that BMP-2 involved in the rat bone remodeling and orthodontic tooth movement, and play a very important role. The experiments revealed BMP-2 in periodontal tissue distribution and the relationship between tooth movement, and further shows BMP-2 on periodontal tissue remodeling has some regulatory role.