用于牙科应用的纳米级氟化钙的制备及性能
Preparation and properties of nano-sized calcium fluoride for dental applications.
作者信息
Sun Limin, Chow Laurence C
机构信息
American Dental Association Foundation Paffenbarger Research Center, Polymers Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8546, USA.
出版信息
Dent Mater. 2008 Jan;24(1):111-6. doi: 10.1016/j.dental.2007.03.003. Epub 2007 May 3.
OBJECTIVES
The aim of the present study was to prepare nano-sized calcium fluoride (CaF(2)) that could be used as a labile F reservoir for more effective F regimens and as an agent for use in the reduction of dentin permeability.
METHODS
Nano-sized CaF(2) powders were prepared using a spray-drying system with a two-liquid nozzle. The properties of the nano-CaF(2) were studied and the effectiveness of a fluoride (F) rinse with nano-CaF(2) as the F source was evaluated. The thermodynamic solubility product of the nano-CaF(2) solution was determined by equilibrating the nanosample in solutions presaturated with respect to macro-CaF(2). Reactivity of the nano-CaF(2) was assessed by its reaction with dicalcium phosphate dehydrate (DCPD). F deposition by 13.2 mmol/L F rinse with the nano-CaF(2) as the F source was determined using a previously published in vitro model.
RESULTS
X-ray diffraction (XRD) analysis showed pattern of low crystalline CaF(2). BET measurements showed that the nano-CaF(2) had a surface area of 46.3m(2)/g, corresponding to a particle size of 41nm. Transmission electron microscopy (TEM) examinations indicated that the nano-CaF(2) contained clusters comprising particles of (10-15) nm in size. The nano-CaF(2) displayed much higher solubility and reactivity than its macro-counterpart. The CaF(2) ion activity product (IAP) of the solution in equilibrium with the nano-CaF(2) was (1.52+/-0.05)x10(-10), which was nearly four times greater than the K(sp) (3.9 x 10(-11)) for CaF(2). The reaction of DCPD with nano-CaF(2) resulted in more F-containing apatitic materials compared to the reaction with macro-CaF(2). The F deposition by the nano-CaF(2) rinse was (2.2+/-0.3)mug/cm(2) (n=5), which was significantly (p<0.001) greater than that ((0.31+/-0.06)mug/cm(2)) produced by the NaF solution.
SIGNIFICANCE
The nano-CaF(2) can be used as an effective anticaries agent in increasing the labile F concentration in oral fluid and thus enhance the tooth remineralization. It can also be very useful in the treatment for the reduction of dentin permeability.
目的
本研究的目的是制备纳米级氟化钙（CaF₂），其可作为不稳定的氟储存库用于更有效的氟治疗方案，并作为降低牙本质渗透性的药物。
方法
使用带有双液喷嘴的喷雾干燥系统制备纳米级CaF₂粉末。研究了纳米CaF₂的性质，并评估了以纳米CaF₂作为氟源进行氟冲洗的效果。通过使纳米样品在相对于宏观CaF₂预饱和的溶液中平衡来测定纳米CaF₂溶液的热力学溶度积。通过纳米CaF₂与磷酸二钙二水合物（DCPD）的反应来评估其反应活性。使用先前发表的体外模型测定以纳米CaF₂作为氟源进行13.2 mmol/L氟冲洗后的氟沉积量。
结果
X射线衍射（XRD）分析显示为低结晶度CaF₂的图谱。BET测量表明，纳米CaF₂的表面积为46.3m²/g，对应粒径为41nm。透射电子显微镜（TEM）检查表明，纳米CaF₂包含由尺寸为（10 - 15）nm的颗粒组成的聚集体。纳米CaF₂表现出比其宏观对应物更高的溶解度和反应活性。与纳米CaF₂平衡的溶液的CaF₂离子活度积（IAP）为（1.52±0.05）×10⁻¹⁰，几乎是CaF₂的溶度积（K(sp)）（3.9×10⁻¹¹）的四倍。与与宏观CaF₂的反应相比，DCPD与纳米CaF₂的反应产生了更多含氟的磷灰石材料。纳米CaF₂冲洗后的氟沉积量为（2.2±0.3）μg/cm²（n = 5），显著（p < 0.001）高于氟化钠溶液产生的氟沉积量（（0.31±0.06）μg/cm²）。
意义
纳米CaF₂可作为一种有效的防龋剂，增加口腔液中不稳定氟的浓度，从而增强牙齿再矿化。它在降低牙本质渗透性的治疗中也非常有用。
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