Regeneración ósea de la sínfisis mandibular usando hidroxiapatita con o sin sinvastatinaefectos en ratas sanas, diabéticas y osteoporóticas

Résumé

Objective: To compare new bone formation in critical defects in healthy, diabetic and osteoporotic rats filled with hydroxyapatite (HA) alone and HA combined with simvastatin (SV). Materials and Methods: A total of 48 adult female Sprague-Dawley rats were randomized into three groups (n=16 per group): Group 1 healthy; Group 2 diabetics; and Group 3 osteoporotics. Streptozotocin was used to induce type-I diabetes in Group 2, while bilateral ovariectomy was used to induce osteoporosis in Group 3. The central portion of the rat mandibular symphysis was used as a physiological critical bone defect. In each group, eight defects were filled with HA alone, and eight with HA combined with SV. The animals were sacrificed at 4 and 8 weeks and the mandibles were processed for: micro-computed tomography to analyze radiological union and bone mineral density (BMD); histological analysis of the bone union; and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2). Results: In all groups (healthy, diabetics and osteoporotics), the defects filled with HA + SV presented greater radiological bone union, BMD, histological bone union and more VEGF and BMP-2 positivity, in comparison with bone defects treated with HA alone. Conclusions: Combined application of HA and SV improves bone regeneration in mandibular critical bone defects compared with application of HA alone in healthy, diabetic and osteoporotic rats. This study might help to patients with osteoporosis or uncontrolled diabetes type I, but future studies should be done.