NANOSTRUCTURED BIOACTIVE MATERIALS

纳米形式的羟基磷灰石、其它磷酸钙化合物和其它生物活性无机化合物 材料将通过新开发的方法制备，采用喷雾干燥或火焰干燥 热解技术，使得（1）可以获得宽范围内的目标粒度，（2） 可以制备具有低溶解度和高溶解度的化合物，以及（3）所制备的颗粒不会 在它们形成后暴露于任何溶液环境，因此将保持它们原始的、高度 反应性表面（Aim 1）。由于它们的小尺寸和高反应性，所制备的纳米材料是 预计将有一系列的临床应用。其中两项将在目标2和3中评价。 目标2将侧重于评估纳米形式氟化钙（CaF 2）作为 氟化物（F）用于矿化牙釉质龋损，使用（1）体外模型以了解 CaF 2粒径与F沉积之间的关系，（2）体内唾液和牙菌斑模型进行比较 由纳米CaF 2和目前使用的NaF漱口液产生的口服F保留，以及（3）原位 使用脱矿/矿化模型来评估纳米CaF 2漂洗剂的矿化效果。 目的3将评估纳米磷酸钙和氟化钙在降低 牙本质渗透性，与牙齿过敏密切相关的特性。

Nano forms of hydroxyapatite, other calcium phosphate compounds, and additional bioactive inorganic materials will be prepared by a newly developed method, employing either a spray drying or a flame pyrolysis technique in such a way that (1) target particle sizes over a wide range can be obtained, (2) compounds with both low and high solubilities can be prepared, and (3) the prepared particles would not be exposed to any solution environment after their formation and therefore would retain their original, highly reactive surfaces (Aim1). Due to their small sizes and high reactivity, the prepared nano materials are expected to have a range of clinical applications. Two of which will be evaluated in Aims 2 and 3. Aim 2 will focus on evaluating the effectiveness of nano forms calcium fluoride (CaF2) as the source of fluoride (F) for remineralizing tooth enamel carious lesions using (1) an in vitro model to understand the relationship between CaF2 particle size and F deposition, (2) an in vivo saliva and plaque model to compare oral F retention produced by the nano CaF2 and currently used NaF rinses, and (3) an in situ demineralization/remineralization model to evaluate the remineralization effects of the nano CaF2 rinse. Aim 3 will evaluate the effectiveness of nano sized calcium phosphates and calcium fluoride in reducing dentin permeability, a property closely associated with dental hypersensitivity.