Cross-linked and non-cross-linked collagen barrier membranes disintegrate following surgical exposure to the oral environment: A histological study in the cat

Background: Early barrier membrane degradation may result in decreased bone formation in guided bone regeneration (GBR) procedures. The aim of this study was to evaluate the bio-degradation of cross-linked (CLM) and non-cross-linked (NCLM) collagen membranes experimentally exposed to the oral environment of study animals. Methods: In eight cats, 48 surgical procedures were performed, three along each side of the palate: 24 full-thickness soft tissue perforations were made and 24 full-thickness mini-flaps were raised. CLM or NCLM discs were placed either under the perforations and peripheral mucosa and left exposed (experimental) or covered by the flaps (controls). The four treatment modalities were equally distributed among the eight animals. Block sections were retrieved at 7 and 28 days post-operatively, providing histological specimens (6 each) at 7 and 28 days for each treatment modality. Results: Histological observation revealed that CLM and NCLM remained intact in the control sites during the 28 days. At 7 and 28 days, CLM appeared interrupted in three and two experimental sites, respectively, and were undetected in the remaining sites. NCLM were interrupted in two sites each at 7 and 28 days, and were undetected in the other sites. There was no statistical difference between control specimens and between CLM and NCLM of the different treatment modalities at 7 or 28 days. Conclusions: Both cross-linked and non-cross-linked membranes were resistant to tissue degradation and maintained continuity throughout the study. However, none of the membranes was resistant to degradation when exposed to the oral environment.