Uso de membrana de polipropileno associada ou não a doxiciclina 10% ou osso bovino em defeito crítico de ratas ovariectomizadas

Abstract

In order to perform the reconstruction of critical bone defects, especially in patients with disorders of bone metabolism such as osteoporosis, several surgical techniques and biomaterials have been developed. The use of polypropylene membrane (Bone Heal®) associated with osteoinductive and/or osteoconductive agents such as Doxycycline 10% and bovine bone can promote adequate bone regeneration in a shorter clinical time and with greater predictability of success in critical bone defects. The objective of this study was to evaluate the use of the non-resorbable polypropylene membrane (Bone Heal®) with 10% Doxycycline gel or bovine bone graft on bone regeneration in calvarial defects of osteoporotic rats. 105 Wistar rats were used, after 16 weeks of ovariectomy surgery a critical bone defect of 6 mm was made in calvaria. The animals were divided into 7 groups (n=15/group): Sham (positive control), OVX (negative control), OVX-MEMB (Bone Heal® membrane) OVX-BIO-MEMB (Bio-Oss and Bone Heal®); OVX-DOX-MEMB (Doxycycline 10% and Bone Heal®); OVX-BIO (Bio-Oss) and OVX-DOX (Doxycycline 10%). After the experimental periods of 4, 8 and 12 weeks euthanasia was performed and the region corresponding to the defect was evaluated in relation to the volume of mineralized tissues (R-MTF) by means of microtomographic analysis and the bone formation that was evaluated by histometric analysis. The Kruskal-Wallis test and the Dunn test were used for comparison between the groups in the different experimental periods and within each group, varying the experimental periods. GraphPad Prism 6 software was used for statistical analysis at the 95% confidence level. In the microtomographic analysis, the R-MTF (%) values in the OVX-MEMB group were higher in the 4-week period when OVX-DOX (p <0.05). In the histometric analysis it was observed that the OVX-BIO- MEMB group had a higher amount of bone (p <0.05) than the OVX group in the 4 and 8 week evaluation periods. It was also found that the OVX-DOX-MEMB group in the 4 week period had a higher amount of bone tissue than the same group over the 12 week period (p <0.05). It is concluded that, both the polypropylene membrane and Bio-Oss and Doxycycline do not present any difference in the bone regeneration of osteoporotic rats, when compared to the blood clot. In addition, the use of polypropylene membrane associated with Bio-Oss can promote a greater bone formation.