Short- and long-term effects of IL-1 and TNF antagonists on periodontal wound healing

The present study tested the effects of local injection of IL-1 and TNF soluble receptors on a periodontal wound-healing model in nonhuman primates. In this model, periodontal lesions were developed for 16 wk, followed by open flap surgery. Starting at the time of surgery, groups of animals received localized injections of both soluble cytokine receptors or else PBS three times per week for 3, 14, or 35 days. Periodontal wound healing was analyzed for each group at the end of the treatment regimen. Fourteen days after surgery, a significant decrease was observed between the animals treated with soluble receptors and the untreated group with respect to recruitment of inflammatory cells in deep gingival connective tissue. Concurrent apoptosis of inflammatory cells in those tissues increased significantly in treated animals compared with untreated animals. All other outcome parameters of periodontal wound healing were likewise significantly improved in treated animals compared with untreated animals. In marked contrast, however, 35 days after surgery, there was a significant increase in the number of inflammatory cells that had infiltrated into deep gingival connective tissue in treated compared with untreated animals. Outcome parameters of periodontal wound healing worsened in treated animals when compared with untreated. These results indicate that proinflammatory cytokines may play different functional roles in early vs late phases of periodontal wound healing. Short-term blockade of IL-1 and TNF may facilitate periodontal wound healing, whereas prolonged blockade may have adverse effects.