Dynamics of Subcutaneous Tissue Response to the Implantation of Tetracycline-Treated or Untreated Membrane of Demineralized Bovine Cortical Bone in Rats

Abstract

This study aims to conduct a histological evaluation of tissue response to a membrane obtained from demineralized bovine cortical bone, associated or not, to tetracycline (TTC). TTC treated and untreated bovine membranes were implanted in the subcutaneous tissue of rats (n = 120). The animals were killed 1, 3, 7, 15, 30, and 60 days after surgery. The tissue around the material was fixed in 10% buffered formalin for 24 h. Sections of 6 mm were stained with hematoxylin and eosin. In general, moderate to intense inflammatory response was observed in the initial periods (1 and 3 days), moderate response in the 7- and 15-day periods, and that was remarkably reduced at 30 and 60 days. Resorptions of the membranes by mononuclear cells (fibroblasts and macrophages) and multinucleated giant cells were observed 15 days after implantation. Only the remnants of the material could be detected in some animals in 60 days. Both membranes were tolerated by the tissue and were completely resorbed after 30-60 days. While the association of TTC apparently accelerated the biodegradability of the membrane substrate, no significant differences were found in the tissue response behavior between the two groups tested.