Three Different Strategies to Obtain Porous Calcium Phosphate Cements: Comparison of Performance in a Rat Skull Bone Augmentation Model
Three Different Strategies to Obtain Porous Calcium Phosphate Cements: Comparison of Performance in a Rat Skull Bone Augmentation Model
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DOI：
10.1089/ten.tea.2011.0444
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发表时间：
2012-06-01
影响因子：
4.1
通讯作者：
Jansen, John A.
中科院分区：
文献类型：
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作者：
Klijn, Reinoud J.;van den Beucken, Jeroen J. J. P.;Jansen, John A.
对于骨量不足的患者，修复前手术已经成为获得足够数量和质量的骨量以安装牙种植体的常规手术。虽然自体骨嵌体或嵌体移植仍然是首选的骨强化技术，但已经开发了一系列的合成骨替代品，例如磷酸钙骨水泥(CPC)。在CPC中引入孔洞可以用来增加CPC的降解和骨的生长。因此，在这项临床前研究中，评估了三种不同的获得多孔性CPC的策略。对瞬时多孔CPC(CPC-IP)和延迟多孔CPC(CPC-IP)进行了体内外比较。CPC-IP是通过在固化过程中产生CO2气泡获得的，而延迟多孔CPC是在聚乳酸-乙醇酸共聚微球(PLGA)降解后得到的。另外，通过加入中空或致密的可降解PLGA微球(CPC-hPLGA和CPC-dPLGA)制备了延迟型多孔CPC。所有CPC组合物都表现出适当的临床操作性能和相互连接的多孔结构，最终孔隙率超过70%(v/v)。体外降解研究表明，含有PLGA微球(dPLGA微球和GT；hPLGA微球)的CPC逐渐形成孔洞，并进一步溶解CPC基质。为了在体内评估CPC，使用了一个增强模型，允许将CPC注射到大鼠头骨上牢固固定的特氟龙环中。植入12周后的组织学评估显示，所有三种CPC均可形成骨。骨附着达到增大面积的10%，最大增大高度接近1 mm。与两种含有PLGA微球的CPC相比，CPC-IP显示了更多的骨形成，并导致了更高的骨沉积高度。含有hPLGA微球和含有dPLGA微球的CPC的生物学性能没有差异。在用于潜在的临床环境之前，需要进一步的研究来提高用于骨增强手术的CPC的骨定位速度和数量。
Preprosthetic surgery has become a routine procedure to obtain sufficient bone quantity and quality for dental implant installation in patients with an initial inadequate bone volume. Although autologous bone onlay or inlay grafting is still the preferred bone augmentation technique, a broad range of synthetic bone substitutes have been developed, for example, calcium phosphate cement (CPC). The introduction of porosity within CPC can be used to increase CPC degradation and bone ingrowth. Therefore, three different strategies to obtain porous CPCs were evaluated in this preclinical study. Instantaneously porous CPC (CPC-IP) was compared with delayed porous CPC in vitro and in vivo. CPC-IP was obtained by the creation of CO2 bubbles during setting, whereas delayed porous CPC was obtained after the degradation of incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres. As an additional aspect, delayed porous CPC was created by the incorporation of either hollow or dense degradable PLGA microspheres (CPC-hPLGA and CPC-dPLGA). All CPC compositions showed appropriate clinical handling properties and an interconnected porous structure with a final porosity above 70% (v/v). In vitro degradation studies showed the gradual formation of pores and further CPC-matrix dissolution for CPCs containing PLGA microspheres (dPLGA microspheres > hPLGA microspheres). For in vivo evaluation of the CPCs, an augmentation model was used, allowing a CPC injection into a rigidly immobilized Teflon ring on the rat skull. Histological evaluation after 12 weeks of implantation showed bone formation using all three CPCs. Bone apposition reached volumetric amounts of up to 10% of the augmentation area and a maximum augmentation height of similar to 1 mm. CPC-IP showed significantly more bone formation and resulted in a superior bone apposition height compared with both CPCs containing PLGA microspheres. No differences in biological performance were observed between the CPCs containing hPLGA and those containing dPLGA microspheres. Further research is necessary to enhance the bone appositional speed and amount of CPCs for bone augmentation procedures before them being used in a potential clinical setting.