Formation of hydroxyapatite in new calcium phosphate cements
Formation of hydroxyapatite in new calcium phosphate cements
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DOI：
10.1016/s0142-9612(97)00119-1
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发表时间：
1998-09-01
期刊：
影响因子：
14
通讯作者：
Ishikawa, K
中科院分区：
文献类型：
--
作者：
Takagi, S;Chow, LC;Ishikawa, K
磷酸四钙（TTCP）以前已被证明是自固化磷酸钙骨水泥的基本成分，形成羟基磷灰石（HA）作为唯一的最终产物，我们在此报告一种新的自固化磷酸钙骨水泥，不含TTCP。这些骨水泥由无水磷酸二钙（DCPA）、二水磷酸二钙（DCPD）、α-磷酸三钙或无定形磷酸钙以及作为钙的附加来源的氢氧化钙或碳酸钙组成。这些粘固剂需要使用磷酸盐（0.2mol/l（-1）或更高）溶液或高pH溶液作为粘固剂液体。骨水泥在相对短的时间（5-30 min）内硬化，并在24 h内形成HA作为主要终产物。24小时样品的径向拉伸强度在0.2至7.5 MPa的范围内。从X射线衍射研究的结果表明，水泥凝固是由水泥液体的高磷酸盐浓度诱导的HA快速形成引起的。由于DCPA和DCPD在高于12.7的pH值（其为磷酸的pK（3））下是高度可溶的，因此通过使用高碱性溶液作为水泥液体也可获得浆料溶液中的高磷酸盐浓度。这些骨水泥的物理化学性质与含TTCP骨水泥的物理化学性质相当，并且预期新骨水泥也具有与含TTCP骨水泥相似的体内特性。(C)1998爱思唯尔科技有限公司版权所有。
Tetracalcium phosphate (TTCP) has been shown previously to be an essential component of self-setting calcium phosphate cements that form hydroxyapatite (HA) as the only end-product, We report herein on a new self-setting calcium phosphate cement that does not contain TTCP. These cements consist of dicalcium phosphate anhydrous (DCPA), dicalcium phosphate dihydrate (DCPD), alpha-tricalcium phosphate, or amorphous calcium phosphate and, as an additional source of calcium, calcium hydroxide or calcium carbonate. These cements require the use of a phosphate (0.2 mol l(-1) or higher) solution or a high pH solution as the cement liquid. The cements harden in relatively short time (5-30 min) and form HA as the dominant end-product in 24 h. The diametral tensile strengths of the 24-h samples are in the range of 0.2 to 7.5 MPa. Results from X-ray diffraction studies suggest that the cement setting is caused by rapid HA formation induced by the high phosphate concentration of the cement liquid. Because DCPA and DCPD are highly soluble at pH values above 12.7, which is the pK(3) of phosphoric acid, high phosphate concentration in the slurry solution was also attainable by using a highly alkaline solution as the cement liquid. The physicochemical properties of these cements are comparable to those of TTCP-containing cements, and the new cements may be expected to have in vivo characteristics similar to those of TTCP-containing cements as well. (C) 1998 Elsevier Science Ltd. All rights reserved.