NANOSTRUCTURED BIOACTIVE MATERIALS

纳米形式的羟基磷灰石、其他钙磷酸盐化合物和附加的生物活性无机 材料将通过一种新开发的方法制备，使用喷雾干燥或火焰 热解技术：(1)可以在很大范围内获得目标颗粒尺寸，(2) 可以制备低溶解度和高溶解度的化合物，以及(3)所制备的颗粒不会 在形成后暴露在任何溶液环境中，因此将保持其原始的、高度的 反应面(Aim1)。由于其尺寸小，反应活性高，所制备的纳米材料 预计将有一系列的临床应用。其中两项将在目标2和目标3中进行评估。 目标2将重点评估纳米形式的氟化钙(CaF2)作为 氟化物(F)用于牙釉质龋损的再矿化：(1)体外模型 氟化钙颗粒大小与氟沉积的关系，(2)唾液和斑块体内模型的比较 由纳米CaF2和目前使用的NaF漱口液产生的口腔氟固位，以及(3)原位 脱矿/再矿化模型，以评估纳米CaF2漂洗的再矿化效果。 目标3将评估纳米磷酸钙和氟化钙在降低 牙本质渗透性，一种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.