Objectives

The aim of this present study was to investigate the effect of setting atmosphere on replacement of apatite cement with new bone both in vitro and in vivo.

Material and methods

Apatite cement consisting of an equimolar mixture of tetracalcium phosphate and anhydrous dicalcium phosphate was mixed with distilled water and allowed to set at 37 °C and 100% relative humidity under 0%_, 5%, and 100% CO₂ atmospheres. X-Ray diffraction and Fourier Transform Infrared Spectroscopy were employed to confirm the carbonate apatite formation. Micro-CT and histological evaluation was made at 1 and 6 month(s) using twelve 10-week-old specific-pathogen-free male Wistar rats.

Results

B-type carbonate apatite was found when the apatite cement was set under 100% CO₂ and 5% CO₂. More carbonate apatite was formed in the case of 100% CO₂ when compared with 5% CO₂, and none was formed under 0% CO₂. Interestingly, unreacted tetracalcium phosphate was significant when apatite cement was set under 0% CO₂, indicating the formation of Ca-deficient hydroxyapatite. When a bone defect of rat tibia was reconstructed in these conditions of apatite cement and sintered hydroxyapatite, replacement of the apatite cement was confirmed 6 months after implantation, whereas no replacement was observed in the case of sintered hydroxyapatite. The amount of replacement of apatite cement with bone was greater, on the order of 100% CO₂ and 5% CO₂, followed by 0% CO₂.

Conclusion

The results obtained in the present study demonstrated that setting atmosphere clearly plays an important role in the replacement of set apatite cement with bone.

中文翻译：

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安：对磷灰石水泥吸收大气中设置的影响在体外和体内研究

目标

这本研究的目的是探讨关于更换与新骨磷灰石水泥固化空气的效果在体外和体内。

材料与方法

将由等摩尔的磷酸四钙和无水磷酸二钙混合物组成的磷灰石水泥与蒸馏水混合，并在0％_， 5％和100％CO _2的气氛下设定在37°C和100％相对湿度下。X射线衍射和傅立叶变换红外光谱法被用来确认碳酸盐磷灰石的形成。使用12只10周龄无特定病原的雄性Wistar大鼠在1和6个月时进行Micro-CT和组织学评估。

结果

当将磷灰石水泥设定在100％CO ₂和5％CO ₂下时，发现了B型碳酸盐磷灰石。与5％CO ₂相比，在100％CO ₂的情况下形成更多的碳酸盐磷灰石，而在0％CO ₂下没有形成。有趣的是，当磷灰石水泥的CO ₂含量设定在0％以下时，未反应的磷酸四钙很显着。，表明缺乏钙的羟基磷灰石的形成。当在这种磷灰石水泥和羟基磷灰石烧结条件下重建大鼠胫骨的骨缺损时，在植入后6个月就证实了磷灰石水泥的置换，而在烧结的羟基磷灰石的情况下未观察到置换。用骨头代替磷灰石水泥的量更大，依次为100％CO ₂和5％CO ₂，接着是0％CO ₂。

结论

在本研究中获得的结果表明，凝结气氛显然在用骨替代凝结磷灰石水泥中起着重要作用。