Modelo de regeneração óssea guiada com o uso de membrana de pericárdio bovino: análise tomográfica e histológica em calvária de coelho

Abstract

Background: The management of bone defects constitutes a good part of the dental surgeon's clinical experience. Guided bone regeneration is a therapeutic modality that aims to promote bone augmentation through the use of barriers that are composed of various materials. The ability to obtain alveolar ridge augmentation has expanded the treatment possibilities in several areas of dentistry. The loss of alveolar bone volume after tooth extraction is an irreversible process that affects both function and aesthetics. Objective: To establish and standardize an experimental model of guided bone regeneration in rabbits for the evaluation of biomaterials for bone grafting. Methodology: Four standardized bone defects were created in the skulls of 18 rabbits and filled with autogenous bone, collagen biomaterial, strontium-added collagen, and an empty defect used as a negative control, so as to enable individual assessment. The defects were also covered with a bovine pericardial membrane with L-Hydro processing. To improve the accuracy of the control scans, a device was developed to stabilize the positioning of the rabbit during the examination. Bone volumetric analyses were performed using CT scans at 30, 60 and 90 days and analyzed with ITK-SNAP® software following the standardization proposed in this study. Histological analysis of the material was performed at 90 days postoperatively. Results: The standardized positioning of the animals was crucial to obtain uniform and comparable measurements between the animals. The volumetric analysis of the newly formed bone showed that there was a reduction in the volume of the bone defects in all defects. Furthermore, in comparison with the empty defect, a significant reduction was observed in all filled defects, indicating greater bone formation in the filled defects. No significant differences in bone formation were observed between defects filled with collagen or collagen + strontium at any time. Histological analysis did not detect any evidence of a chronic inflammatory process, nor an accentuated number of osteoclasts. The bovine pericardial membrane was positioned between the neoformed bone and the adjacent skin in all analyses, proving its efficacy as a barrier. Conclusion: The experimental model and the techniques used to evaluate the repair proved to be adequate and with potential for reproduction. The bovine pericardium membrane presented itself as a good barrier option for guided bone regeneration, especially in more extensive bone defects.