Kitsugi T, Yamamuro T, Nakamura T, Kotani S, Kokubo T, Takeuchi H
Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Japan.
Biomaterials. 1993 Feb;14(3):216-24. doi: 10.1016/0142-9612(93)90026-x.
Calcium phosphate ceramics, beta-calcium pyrophosphate (Ca2P2O7), beta-tricalcium phosphate (Ca3(PO4)2), hydroxyapatite (Ca10(PO4)6(OH)2) and tetracalcium phosphate (Ca4(PO4)2O), were prepared. The calcium:phosphorus ratios and microporosities were 1 (31.6%), 1.5 (1.6%), 1.66 (1%) and 2 (34.6%) respectively. Samples (15 mm x 10 mm x 2 mm), abraded with No. 2000 alumina powder, were implanted into the tibial metaphysis of mature male rabbits. Failure load, when an implant detached from the bone or the bone itself broke, was measured. At 10 wk after implantation, the failure loads in beta-calcium pyrophosphate, beta-tricalcium phosphate, hydroxyapatite and tetracalcium phosphate were 31.65 +/- 9.90 N, 72.81 +/- 19.01 N, 49.49 +/- 17.25 N and 43.22 +/- 14.99 N respectively. At 25 wk after implantation, the values were 47.04 +/- 14.90 N, 71.34 +/- 19.50 N, 69.09 +/- 16.17 N and 62.03 +/- 18.62 N respectively. Histologically, bone bonding behaviour of calcium phosphate ceramics did not vary with the calcium:phosphorus ratio, as observed by contact microradiogram, Giemsa surface staining and scanning electron micrograph-electron probe micro analysis. There was no intervening soft tissue at the interface of bone and ceramics. Hydroxyapatite or tricalcium phosphate are used as bone substitutes. However, their mechanical strength is insufficient for weight-bearing and they are used as bone filler. This study showed that the apparent insignificance of strict calcium:phosphorus ratio with respect to the biological results greatly simplifies processing of calcium phosphate ceramics for clinical application. In clinical application, calcium phosphate ceramics with different Ca:P can be used as bone fillers for bone defects or bone cavities under non-weight-bearing conditions.
制备了磷酸钙陶瓷，包括β-焦磷酸钙（Ca2P2O7）、β-磷酸三钙（Ca3(PO4)2）、羟基磷灰石（Ca10(PO4)6(OH)2）和磷酸四钙（Ca4(PO4)2O）。钙磷比和微孔率分别为1（31.6%）、1.5（1.6%）、1.66（1%）和2（34.6%）。将用2000号氧化铝粉末研磨过的样本（15毫米×10毫米×2毫米）植入成年雄性兔的胫骨干骺端。测量当植入物从骨上分离或骨本身断裂时的失效载荷。植入后10周，β-焦磷酸钙、β-磷酸三钙、羟基磷灰石和磷酸四钙的失效载荷分别为31.65±9.90牛、72.81±19.01牛、49.49±17.25牛和43.22±14.99牛。植入后25周，这些值分别为47.04±14.90牛、71.34±19.50牛、69.09±16.17牛和62.03±18.62牛。组织学上，通过接触微射线照相、吉姆萨表面染色和扫描电子显微镜-电子探针微分析观察到，磷酸钙陶瓷的骨结合行为并不随钙磷比而变化。在骨与陶瓷的界面处没有中间软组织。羟基磷灰石或磷酸三钙用作骨替代物。然而，它们的机械强度不足以承受重量，因此用作骨填充剂。本研究表明，严格的钙磷比对生物学结果明显无显著影响，这大大简化了磷酸钙陶瓷临床应用的加工过程。在临床应用中，不同钙磷比的磷酸钙陶瓷可在非负重条件下用作骨缺损或骨腔的骨填充剂。
