The effect of the platelet-derived growth factor on the cellular response of the periodontium: An autoradiographic study on dogs The purpose of this study was to see the effect of PDGF on the pattern of proliferation and migration of fibroblast with and without barrier membranes. Six adult mongrel dogs were used for this study. Dogs were sedated. Initial prophylaxis consisted of hand scaling root planing and tooth polishing. Oral hygiene was maintained by daily brushing with 0.12% chlorhexidine five times per week. Four birooted teeth in both quadrants of the mandibular arch were used, second (P2), third (P3), and fourth (P4) premolars, and first molars (M).Two dogs were used for each type of procedure. The modalities of procedure were as follows: control group (no membrane), group with an ePTFE membrane, ePTFE + PDGF, and PDGF only. Fenestrations were cut through the bone to expose the middle half of the root. Cementum was completely removed. The dogs were sacrificed at 1, 3, and 7 days following surgery. Titrated thymidine was injected for labeling of the cells in ³S² phase of mitosis.
When all time periods and noninflammatory cells were counted, both PDGF/ePTFE and PDGF showed increased cell proliferation when compared to control. Labeled cells obscured the trends seen before due to the predominance of inflammatory cells in most slides. The cellular response decreased from day 1 to day 7. At day 7 all groups with PDGF showed an increased number compared to control group and membranes alone. The total of labeled cells decreased from day 1 to day 7 in the control group. The ePTFE group showed more activity at day 1 and less activity at days 3 and 7. PDGF showed most activity at day 7 (there were PDL fibroblasts into the defect).The group of ePTFE/PDGF was very similar to the group PD G F and PDL fibroblasts were H bridging." Fibroblasts showed a moderate cellular activity at day 1, decreasing at day 3 and dramatically increasing at day 7. At day 7 the PDGF group showed the greatest activity (significantly different from control and membrane alone), followed by the combined treatment ePTFE/PDGF. In the cementoblast the labeling was least at day 3 and the greatest at day 7 for all the groups except the control. Only PDGF was significantly different from the control. Osteoblast labeling activity was very similar to the cementoblasts (labeling was greatest for PDGF at day 7). Perivascular cells exhibited the highest degree of cell activity at day 7 for all but the control group. (Both PDGF treatments were significantly different from the control at day 7.) Endothelial cells showed the highest activity for both PDGF groups at day 7. (Statistical differences existed only between the ePTFE/PDGF and control group at day 7.)
In conclusion, application of PDGF in periodontal close wounds enhanced the proliferation of fibroblasts. The implantation of membranes had no effect on fibroblast proliferation at wound sites. The prevalence of inflammatory cells was greater in the groups treated with it. Discrete cell activity was observed among cementoblasts and osteoclasts at day 7. Perivascular and endothelial cells were slightly more active in specimens treated with PDG. [c.c.]
Wang H.L.,T.D. Pappert, W.A. Castelli, D.J. Chiego, Y. Skyr, and B.A. Smith, J Periodont,65:429, 1994