Abstract
It is well known that preservation of the cementum on the root surface is advantageous for periodontal regeneration.
This effect may be attributable to the presence of growth factors in the cementum. In this study, we determined the presence and measured the levels of BMP-2 and TGF-β1 in the cementum and compared them with those in dentin. The root of the human third molars was cut into 0.5mm thick slices, and the slices were demineralized with 0.1M HCl solution. The cementum and dentin were separated using a sharp blade under a microscope. Then, the samples were extracted with 4M guanidine solution. The alkaline phosphatase (ALP) activity of the extracts was detected using human periodontal ligament (HPDL) cells and C2C12 cells and compared between the cementum and dentin.
TGF-β1 and BMP-2 were detected by the luciferase reporter gene assay. We observed reciprocal inhibiory activity between BMP-2 and TGF-β1, therefore, the ALP activity of each of the growth factos was measured using Noggin (a BMP-2 inhibitor) and SB431542 (a TGF-β1 inhibitor). We calculated the amount of active type TGF-β1 and BMP-2 in each extract based on the ALP activity of recombinant TGF-β1 and BMP-2. The results revealed the presence of TGF-β1 at 35.8pg of BMP-2 at 193pg and a BMP-2/ TGF-β1 ratio of 5.39 in the cementum and the presence of TGF-β1 at 58.6pg, of BMP-2 at 241pg and a BMP-2/TGF-β1 ratio of 4.11 in dentin. These results suggest the possibility that cementum, which has a higher as amount of BMP-2, induces osteoblast cells to a greater degree as compared to dentin. Nihon Shishubyo Gakkai Kaishi (J Jpn Periodontol) 49 : 139-150,2007.
