The effects of transforming growth factor-beta on the viability of human periodontal ligament cell and on the experimental tooth movement in rat

Park, Yun Kyung; Kim, Sang Cheol

Abstract

The purpose of this study was to evaluate the effects of Transforming Growth Factor-beta (TGF-beta ) on the viability of human periodontal ligament cells, in-vitro and on the experimental tooth movement in rat, in-vivo. Human periodontal ligaments were cultured from the first premolar tooth extracted for the purpose of the orthodontic treatment. 0.1, 1, 5 and 10ng/ml of TGF-beta was given to the cultured wells, respectively and the viability was evaluated by MTT assay. Twenty Sprague-Dawley rats were divided into 5 experimental groups(4 rats in each) where 100g of force was applied from helical spring across the maxillary incisors. TGF- beta was injected via Hamilton syringe into the periodontal ligament at the mesial and the distal surface of a maxillary incisor of 2 rats in each experimental group. Phosphate buffer saline(PBS) was injected in 2 other rats as controls. Experimental groups were sacrificed at 1, 3. 7. 14 and 28 days after force application, respectively. The obtained tissues were evaluated histologically. The obtained results were as follows: 1.The viability of periodontal ligament cells in 0.1ng/ml of TGF-beta was not significantly different from that of control at 1-, 2- and 3-day of cultivation. 2.The viability of periodontal ligament cells was significantly increased at 3-day in 1ng/ml or 5ng/ml of TGF-beta, and at 2-, 3-day in 10ng/ml of of TGF-beta. 3. The zone of hyalinization in periodontal ligament in pressure side was smaller in TGF-beta injection group than that in control group at 3-day after the application of experimental force in rat. But no difference was seen after 7-day. 4.Osteoclastic activity and capillary prolieferation in pressure side were, greater in TGF-beta injection group than that in control group at 3-day to 7-day. 5.0steoblastic activity and new bone fomation in tension side were greater in TGF-beta injection group than that in control group at 3-day to 14-day.