Effect of recombinant human platelet-derived growth factor-BB and bone morphogenetic protein-2 application to demineralized dentin on early periodontal ligament cell response

The purpose of this study is to investigate the early responses of human periodontal ligament cells attached to recombinant human platelet-derived growth factor-BB and bone morphogenetic protein-2 applied EDTA-demineralized dentin. One hundred and seventy-four root-planed flat dentin blocks were prepared from the mid-third of periodontally diseased human tooth roots. After demineralization with 24% EDTA (pH 7.02) 120 dentin blocks were treated with 0.5 and 1 microgram/ml rhPDGF-BB, 1 and 3 micrograms/ml rhBMP-2 and only MEM as control (24/group). Human periodontal ligament cells (HPLC) were seeded on these dentin surfaces and incubated. The alkaline phosphatase (ALP) activity and protein concentration of the attached cell were assessed at d 2, 4 and 7. Fifty-four dentin blocks were seeded with HPLC after application of 1 microgram/ml rhPDGF-BB, 3 micrograms/ml rhBMP-2 and MEM (18/group) and then incubated. At d 2, 4 and 7, the attached cells were stained and counted under light microscope. The results showed a significant increase of protein concentration and cell number in PDGF-BB treated groups than control (p < 0.05, p < 0.01) but not the ALP activity, and a significant increase of ALP activity was observed in BMP-2 treated groups than control (p < 0.05) but protein concentration and cell number remained almost the same over time. Thus, rhPDGF-BB and rhBMP-2 application to EDTA demineralized dentin surfaces promote the early human periodontal ligament cell responses by increasing cell proliferation and differentiation, respectively, which would ultimately enhance periodontal regeneration.