Plymouth University Peninsula Schools of Medicine and Dentistry, Universities of Exeter & Plymouth, Research Way, Plymouth, United Kingdom.
Dent Mater. 2013 Feb;29(2):166-73. doi: 10.1016/j.dental.2012.11.008. Epub 2012 Dec 4.
Currently, most titanium implant coatings are made using hydroxyapatite and a plasma spraying technique. There are however limitations associated with plasma spraying processes including poor adherence, high porosity and cost. An alternative method utilising the sol-gel technique offers many potential advantages but is currently lacking research data for this application. It was the objective of this study to characterise and optimise the production of Hydroxyapatite (HA), fluorhydroxyapatite (FHA) and fluorapatite (FA) using a sol-gel technique and assess the rheological properties of these materials.
HA, FHA and FA were synthesised by a sol-gel method. Calcium nitrate and triethylphosphite were used as precursors under an ethanol-water based solution. Different amounts of ammonium fluoride (NH4F) were incorporated for the preparation of the sol-gel derived FHA and FA. Optimisation of the chemistry and subsequent characterisation of the sol-gel derived materials was carried out using X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). Rheology of the sol-gels was investigated using a viscometer and contact angle measurement.
A protocol was established that allowed synthesis of HA, FHA and FA that were at least 99% phase pure. The more fluoride incorporated into the apatite structure; the lower the crystallisation temperature, the smaller the unit cell size (changes in the a-axis), the higher the viscosity and contact angle of the sol-gel derived apatite.
A technique has been developed for the production of HA, FHA and FA by the sol-gel technique. Increasing fluoride substitution in the apatite structure alters the potential coating properties.
目前，大多数钛植入物涂层都是使用羟基磷灰石和等离子喷涂技术制成的。然而，等离子喷涂工艺存在一些局限性，包括附着力差、孔隙率高和成本高。另一种方法是利用溶胶-凝胶技术，该方法具有许多潜在的优势，但目前在该应用中缺乏研究数据。本研究的目的是利用溶胶-凝胶技术对羟基磷灰石（HA）、氟羟基磷灰石（FHA）和氟磷灰石（FA）进行特性描述和优化，并评估这些材料的流变性能。
采用溶胶-凝胶法合成 HA、FHA 和 FA。硝酸钙和三乙膦酸酯在乙醇-水基溶液中作为前体使用。为了制备溶胶-凝胶衍生的 FHA 和 FA，加入了不同量的氟化铵（NH4F）。使用 X 射线衍射（XRD）和差示热分析（DTA）对溶胶-凝胶衍生材料的化学性质进行优化和后续特性描述。使用粘度计和接触角测量来研究溶胶的流变性。
建立了一种允许合成至少 99%相纯 HA、FHA 和 FA 的方案。氟化物在磷灰石结构中的掺入量越多，磷灰石的结晶温度越低，单位晶胞尺寸（a 轴的变化）越小，溶胶-凝胶衍生磷灰石的粘度和接触角越高。
已经开发出一种通过溶胶-凝胶技术生产 HA、FHA 和 FA 的技术。增加磷灰石结构中的氟取代会改变潜在的涂层性能。
