Sá M J C, Rezende C M F, Silva Junior V A, Garcia H C, Griffon D J, Silva V V
School of Veterinary, Federal University of Minas Gerais State Av Antônio Carlos, 6627, CP 567, Pampulha CEP 30161-970, Belo Horizonte, MG, Brazil.
J Biomater Appl. 2007 Jul;22(1):5-31. doi: 10.1177/0885328206065860.
The main goal of this study is to evaluate potential applications of two zirconia-hydroxyapatite composites, Z4H6 and Z6H4, as bone substitutes. Composite plugs were implanted into the distal femoral metaphysis and also onto the longissimus dorsi of 18 adult mixed-breed dogs in order to assess in vivo biocompatibility by immediate clinical and radiographic evaluation 30, 90, and 120 days after implantation. Radiographic examination revealed radiolucency on the defect site. However, a progressive increase in bone density was observed over time, reaching a radiopacity similar to that of bone 120 days after implantation. Histological study revealed that a thin layer of fibroblasts was observed at the implant-bone interface in addition to osteoblastic activity 30 days after implantation, whereas bone neoformation around the implants was detected for the subsequent implantation times (90 and 120 days). Otherwise, the histological evaluation of the implant-muscle interface showed the presence of an initially thick fibrous tissue layer 30 days after implantation, which decreased with longer investigation times (90 and 120 days). The numbers of plasmocytes, lymphocytes, and macrophages gradually reduced as a function implantation time, being completely absent 120 days after implantation with a resulting complete osteointegration process. The zirconia phase content did not affect the bioactive behavior of the implants investigated and did not induce bone formation when implanted into muscle either.
本研究的主要目的是评估两种氧化锆-羟基磷灰石复合材料Z4H6和Z6H4作为骨替代物的潜在应用。将复合栓植入18只成年杂种犬的股骨干骺端远端以及背最长肌上，以便通过植入后30、90和120天的即时临床和影像学评估来评估体内生物相容性。影像学检查显示缺损部位有透射性。然而，随着时间的推移，观察到骨密度逐渐增加，在植入后120天达到与骨相似的不透射线性。组织学研究显示，植入后30天，除了成骨细胞活性外，在植入物-骨界面观察到一层薄薄的成纤维细胞，而在随后的植入时间（90和120天）检测到植入物周围有新骨形成。否则，植入物-肌肉界面的组织学评估显示，植入后30天存在最初较厚的纤维组织层，随着研究时间延长（90和120天）该层厚度减小。浆细胞、淋巴细胞和巨噬细胞的数量随着植入时间逐渐减少，在植入后120天完全消失，从而形成完整的骨整合过程。氧化锆相含量不影响所研究植入物的生物活性行为，植入肌肉时也不诱导骨形成。
