Study On Expression Of TGF-β3 And MMP-2 During Mouse Tooth Germs Development Before And After Implanted Into Oral Submucosa

Objective: To study the expression and distribution of TGF-β3 and MMP-2 before and after mouse tooth germs implanted into submucosa, and to investigate the regulation role of TGF-β3 and MMP-2 during the development of tooth germs after advanced bell stage, and to analyze the micro regulation mechanism of tooth germ grafting.Method:1. Inbred strain mouse tooth germs at 4, 11 and 18days postnatal of non-implant group were taken out, and tooth germs at 1 and 2 weeks after grafting were retrieved. After routine fixation,decalcification, embedding and slicing,the expression of TGF-β3 in the tooth germs was detected by immunohistochemisty.2. Inbred strain mouse's tooth germs at 4, 7, 11 and 18days postnatal of non-implant group were taken out, and tooth germs at 1 and 2 weeks after grafting were retrieved. After routine fixation,decalcification, embedding and slicing,the expression of MMP-2 in the tooth germs was detected by immunohistochemisty.Result:1. The immunohistochemical expressions of TGF-β31.1 Non-implant group:In the 4dpn tooth germ there were strong positive expressions on enameloblasts and odontoblasts , positive expressions on ambitus of dental pupilla,and wake positive expressions on the intermedial of dental papilla. In the 11dpn tooth grem there were wake positive expressions on enameloblasts,and negative expressions on odontoblasts and dental papilla. In the 18dpn tooth there were positive expressions on the vessel wall and its surrounding , negative expressions on other areas.1.2 Implant group:In the tooth germ 1 week after grafting there were positive expressions on odontoblast of the tooth cervical part and the surrounding epithelium,and nagetive expressions on other odontoblasts and enameloblasts. In the tooth germ 2 weeks after grafting there were positive expressions only on the surrounding epithelium, others were negative staining, like odontoblasts and enameloblasts.2. The immunohistochemical expressions of MMP-22.1 Non-implant group: In the 4dpn tooth germ there were strong positive expressions on external enamel epithelium,enamel pulp and stratum intermedium, odontoblasts,predentine and dental papilla were positive staining, enameloblasts were negative. In the 7dpn tooth germ there were strong positive expressions on external enamel epithelium,enamel pulp,stratum intermedium and odontoblasts beside hertwig epithelial root sheath , dental papilla was positive staining, other odontoblasts and detine were weak positive , and enameloblasts were negative. In the 11dpn tooth germ positive expressions were detected on intermedial dental pulp, predentine was weak positive staining, odontoblasts and enameloblasts were negative. In the 18dpn tooth there were negative expressions in parodontium ,odontoblasts and dental cementum .2.2 Implant group :In the tooth germ 1 week after grafting there were strong positive expressions on surrounding epithelial tissue , odontoblasts,enameloblasts and dental papilla were positive staining. In the tooth germ 2 weeks after grafting there were strong positive expressions on the surrounding epithelial tissue , negative on the tissue of tooth.Conclusion:1. The expressions of TGF-β3 and MMP-2 have a space-time distribution characteristic during the mouse tooth germ development from advanced bell stage to maturity,therefore they are likely to have some effect on tooth development,and the effect may drop off with the development of tooth germs.2. TGF-β3 and MMP-2 may play a certain regulation role in the development of grafted mouse tooth germs.