Dynamics of bone healing after osteotomy with piezosurgery or conventional drilling– histomorphometrical, immunohistochemical, and molecular analysis

Abstract

Abstract Background Piezosurgery is an osteotomy system used in medical and dental surgery. Manystudies have proven clinical advantages of piezosurgery in terms of quality ofcut, maneuverability, ease of use, and safety. However, few investigations havetested its superiority over the traditional osteotomy systems in terms of dynamicsof bone healing. Therefore, the aim of this study was to evaluate the dynamics ofbone healing after osteotomies with piezosurgery and to compare them with thoseassociated to traditional bone drilling. Methods One hundred and ten rats were divided into two groups with 55 animals each. Theanimals were anesthetized and the tibiae were surgically exposed to create defects2 mm in diameter by using piezosurgery (Piezo group) and conventionaldrilling (Drill group). Animals were sacrificed at 3, 7, 14, 30 and 60 dayspost-surgery. Bone samples were collected and processed for histological,histomorphometrical, immunohistochemical, and molecular analysis. The histologicalanalysis was performed at all time points (n = 8) whereas thehistomorphometrical analysis was performed at 7, 14, 30 and 60 dayspost-surgery (n = 8). The immunolabeling was performed to detectVascular Endothelial Growth Factor (VEGF), Caspase-3 (CAS-3), Osteoprotegerin(OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), andOsteocalcin (OC) at 3, 7, and 14 days (n = 3). For the molecularanalysis, animals were sacrificed at 3, 7 and 14 days, total RNA wascollected, and quantification of the expression of 21 genes related to BMPsignaling, Wnt signaling, inflammation, osteogenenic and apoptotic pathways wasperformed by qRT-PCR (n = 5). Results Histologically and histomorphometrically, bone healing was similar in both groupswith the exception of a slightly higher amount of newly formed bone observed at30 days after piezosurgery (p < 0.05). Immunohistochemical andqRT-PCR analyses didn’t detect significant differences in expression of allthe proteins and most of the genes tested. Conclusions Based on the results of our study we conclude that in a rat tibial bone defectmodel the bone healing dynamics after piezosurgery are comparable to thoseobserved with conventional drilling.