Yu Qinghua, Liu Hongyan, Liu Zhiguo, Peng Yan, Cheng Xiaoning, Ma Ke, Ji Yakun
Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, P.R. China.
Department of Oral and Maxillofacial Surgery, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, P.R. China.
Am J Dent. 2017 Apr;30(2):109-115.
To evaluate the viability of a series of nano-fluoridated hydroxyapatite (nano-FHA) formulations of varying fluoride content for the occlusion of exposed dentin tubules, in comparison to nano-hydroxyapatite (nano-HA).
Nano-FHA powders with varying levels of fluoride ion were synthesized to substitute hydroxyl ions (⁻OH) present in hydroxyapatite (HA). Nano-FHA were defined as 2nFHA,4nFHA,6nFHA, 8nFHA and 10nFHA, with the molar ratio of F(⁻ to Ca243; of 0.002,0.004,0.006,0.008 and 0.01, respectively. The powders were synthesized using a wet chemistry route, and characterized by transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The methylthiazol tetrazolium (MTT) assay was used to assess cell viability toward nano-FHA. According to the content of F⁻, the nano-nFHA and nano-HA powders were divided into six groups, with the artificial saliva as control. They were spread over the dentin surface for 1 minute and repeated three times per day for 7 consecutive days. After washing and brushing with distilled water for an additional 7 days, scanning electron microscopy was used to evaluate the in vitro plugging rate of the tubules and penetrating depth.
The 2nFHA, 4nFHA, 6nFHA, 8nFHA and 10nFHA powders were prepared and characterized. The 8nFHA had less crystallinity compared to 2nFHA,4nFHA, and 6nFHA.The MTT assay (from 12 to 120 hours) showed that the cell viability of the L-929 fibroblasts in the 2nFHA, 4nFHA, 6nFHA, 8nFHA, 10nFHA, and nano-HA groups ranged from 80.54± 3.35% to 112.9± 4.8%. Most of the nano-FHA powders successfully occluded dentin tubules. The plugging rate of 8nFHA was significantly higher than that of the 2nFHA, 4nFHA, 6nFHA and nano-HA groups. The penetrating depth of the 8nFHA group into the tubules was also significantly higher than that of the other nano-FHA and nano-HA group.
The nano-FHA formulation 8nFHA showed higher plugging rate and penetrating depth into the tubules. It has the potential to be used as a desensitizing agent in treating dentin hypersensitivity with better long-term durability and efficacy of dentin tubule occlusion.
与纳米羟基磷灰石（nano-HA）相比，评估一系列氟含量不同的纳米氟化羟基磷灰石（nano-FHA）制剂封闭暴露牙本质小管的可行性。
合成了具有不同氟离子水平的纳米FHA粉末，以替代羟基磷灰石（HA）中存在的氢氧根离子（⁻OH）。纳米FHA被定义为2nFHA、4nFHA、6nFHA、8nFHA和10nFHA，F⁻与Ca²⁺的摩尔比分别为0.002、0.004、0.006、0.008和0.01。采用湿化学法合成这些粉末，并通过透射电子显微镜、X射线衍射和傅里叶变换红外光谱对其进行表征。采用甲基噻唑四氮唑（MTT）法评估细胞对纳米FHA的活力。根据F⁻含量，将纳米nFHA和纳米HA粉末分为六组，以人工唾液作为对照。将它们铺展在牙本质表面1分钟，每天重复3次，连续7天。再用蒸馏水冲洗和刷牙7天后，使用扫描电子显微镜评估小管的体外封闭率和渗透深度。
制备并表征了2nFHA、4nFHA、6nFHA、8nFHA和10nFHA粉末。与2nFHA、4nFHA和6nFHA相比，8nFHA的结晶度较低。MTT法（12至120小时）显示，2nFHA、4nFHA、6nFHA、8nFHA、10nFHA和纳米HA组中L-929成纤维细胞的细胞活力在80.54±3.35%至112.9±4.8%之间。大多数纳米FHA粉末成功封闭了牙本质小管。8nFHA的封闭率显著高于2nFHA、4nFHA、6nFHA和纳米HA组。8nFHA组进入小管的渗透深度也显著高于其他纳米FHA和纳米HA组。
纳米FHA制剂8nFHA显示出更高的封闭率和进入小管的渗透深度。它有潜力用作治疗牙本质过敏的脱敏剂，具有更好的长期耐久性和牙本质小管封闭效果。
