Healing of experimental oral wounds following application of a hemostatic agent in dogs

ABSTRACT

The purpose of this study was to investigate the effect of a hemostatic agent [Hemocollagene] and evaluate the tissue-material interaction during the healing of experimental oral mucosa wounds in dogs. Sixteen mature dogs were used in this experiment. Scalpel incision wounds of standard size [2cm long and 1cm deep] were made on both sides of the buccal mucosa. The Hemocollagene was applied to one side [experimental] of the buccal mucosa while the opposite side was used as a control [no hemostatic agent]. Biopsy specimens of the wounds were taken at 4, 10, 20 and 45 days after the operation for evaluation by light microscopy. Clinically no signs of wound dehiscence, inflammation, or infection of the control and experimental sites at 4, 10, 20 and 45 days were noticed. Clinically the Hemocollagene did not affect the quality or the rate of healing. At 4-days, microscopic examination of both control and experimental wound sites showed an inflammatory reaction, which consisted of mononuclear cells, plasma cells and polymorphonuclear leukocytes. Fibroblastic and endothelial proliferation was present. In addition, experimental wound sites showed fragmented partially digested Hemocollagene, which penetrated by neutrophils and erythrocytes. In 10-days specimens, both the control and experimental wound sites showed a dense sheets of fibroblastic and capillary infiltration. The experimental wound sites showed less amounts of digested hemocollagene. In the 20-days specimens, the control and experimental would sites were well epithelialized with the lamina propria composed of numerous lightly woven, streaming interwinning collagen fibers. Areas of chronic inflammatory cells were scattered through out the specimen. The experimental wound sites showed no digested Hemocollagene. The 45-days control and experimental specimens exhibited a well-healed, epithelial layer with a few areas of chronic inflammatory cell remained, especially in association with the small blood vessels. The connective tissue appeared more saturated than at 20-days. No apparent differences in the healing between the control and experimental wound sites. Hemocollagene is well tolerated, undergo biodegradation with no adverse or structural changes, provide no barrier to the normal wound healing process, and does not affect the rate of healing of experimental oral mucosa wounds in dog