Abstract
The purpose of periodontal surgery is to promote the recovery of periodontal tissue which is lost due to advanced periodontal disease. For better regeneration of this tissue, favorable wound healing is required.
In this study, the effect of basic fibroblast growth factor (bFGF), platelet-derived growth factor PDGF) andtransforming growthfactor beta (TGF-β on the changes of distribution of fibrone-c. tiAn) and laminin in wound periodontal tissue of rats after a flap operation were examined.
Full-thickness flap operation was performed on the palatal gingiva at the molar portion in male Wistar rats. After the roots were surgically exposed and planed, the growth factors (10 ng/3μl) were injected into the palatal gingiva with a microliter syringe. Animals were sacrificed at 1, 3, 5 and 7 days after the injection of these factors. The specimens were fixed with PLP solution, decalcified with EDTA, made into serial paraffin sections, and stained with hematoxylin and eosin (H. E.). The distributions of fibronectin and laminin were demonstrated by indirect immunofluorescence.
In H. E. staining, it was demonstmated that TGF-β. continually enhanced inflammation and in -creased new gingival connective tissue volume and angiogenesis. In the control group, fibronectin was localized in exuded fibrin clots along the line where the flap was made. In the bFGF group, fibronectin was observed under the flap from the early stage of wound healing. In the PDGF group, it was observed under the flap at one day after the operation and along with the bundle of collagenous fibers at 7 days. In theTGF-β group, the fluorescence of fibronectin was strongly positive in the increased granulation tissue as compared with the controls. TGF-β delayed the decrease in fibronectin, interms of maturation of the gingival connective tissue. In the control group, laminin distributed along with the basement membrane of normal epithelium and regenerating epithelium, and the internal surface of blood vessels. In some portions of regenerating epithelium, PDGF andTGF-β delayed the elongation of distribution of laminin as compared with controls. In theTGF-β group, the width of the distribution of laminin had enlarged at the basement membrane of regenerative epithelium by the 5th post-operative day.
These results suggest that bFGF, PDGF and TGF-β. A may give an impetus to exudefibronectin into periodontal tissue in wound healing. From the findings of TGF-β. A injected rats, TGF-β. A may play an important role in the wound healing process in periodontal tissue.
