[纳米羟基磷灰石对酸蚀牙本质小管表面矿化及铅离子吸附的影响]
[Effect of nanohydroxyapatite on surface mineralization in acid-etched dentinal tubules and adsorption of lead ions].
作者信息
Yang Jianzhen, Yuan Peiyan, Liu Chengxia, Liu Ping, Ning Huili, Xu Pingping
机构信息
Department of Endodontics, Stomatological Hospital, Southern Medical University/Guangdong Provincial Hospital of Stomatology, Guangzhou 510280, China.
出版信息
Nan Fang Yi Ke Da Xue Xue Bao. 2020 Sep 30;40(9):1307-1312. doi: 10.12122/j.issn.1673-4254.2020.09.13.
OBJECTIVE
To study the effect of nanohydroxyapatite (nHA) for promoting surface mineralization of demineralized dentin discs and adsorption of lead ions in simulated sewage water.
METHODS
Sixty dentin disks were prepared from freshly extracted teeth with intact crown (including 30 premolars and 30 molars) and treated with 10% citric acid for 2 min to simulate dentinal tubules with dentin hypersensitivity. The etched dentin discs were brushed with distilled water, 0.2 g HA or 0.2 g nHA for 2 min twice a day for 7 consecutive days, after which scanning electron microscopy (SEM) was performed and calcium and phosphorus contents in the dentin discs were detected using EDS. Lead ion adsorption capacities of HA and nHA were tested by mixing 1 mL serial concentrations of HA and nHA suspensions with 50 mL lead ion solutions (1.0 mg/L). After 24 h, the residual lead ion concentration in the supernatant was measured using ICP to calculate lead ion adsorption rate and adsorption capacity of the materials.
RESULTS
SEM showed a smooth surface and empty dentin tubules in the acid- etched dentin dics. The dentin dics treated with HA were covered with masses of particles that loosely attached to the surface, and the diameter of the dentin tubules was reduced. In nHA group, the dentin discs showed a fine and homogeneous surface clogging with a tight attachment, and the dentin tubule diameter was obviously reduced. Daily brushing with HA and nHA, especially the latter, significantly increased calcium and phosphorus contents on the surface of the dentin dics ( < 0.000). In lead ion adsorption experiment, the lead ion adsorption rate of HA decreased as its concentration increased with the highest adsorption rate of 83.01%; the adsorption rate of nHA increased with its concentration until the adsorption equilibrium was reached, and its highest adsorption rate was 98.79%. A good liner relationship was found between the adsorption ability and concentration of HA.
CONCLUSIONS
Compared with HA, nHA has a better capacity for surface mineralization of acid-etched dentin discs and also a better ability of lead ion adsorption.
目的
研究纳米羟基磷灰石（nHA）对脱矿牙本质片表面矿化及模拟污水中铅离子吸附的影响。
方法
从新鲜拔除的完整牙冠牙齿（包括30颗前磨牙和30颗磨牙）制备60个牙本质片，用10%柠檬酸处理2分钟以模拟牙本质过敏的牙本质小管。用蒸馏水、0.2 g HA或0.2 g nHA每天两次、每次2分钟连续刷蚀刻后的牙本质片7天，之后进行扫描电子显微镜（SEM）观察，并用能谱仪（EDS）检测牙本质片中钙和磷的含量。通过将1 mL不同浓度的HA和nHA悬浮液与50 mL铅离子溶液（1.0 mg/L）混合来测试HA和nHA对铅离子的吸附能力。24小时后，用电感耦合等离子体质谱仪（ICP）测量上清液中残留的铅离子浓度，以计算材料的铅离子吸附率和吸附容量。
结果
SEM显示酸蚀刻牙本质片中表面光滑，牙本质小管为空管。用HA处理的牙本质片表面覆盖有大量松散附着的颗粒，牙本质小管直径减小。在nHA组，牙本质片表面呈现精细且均匀的堵塞，附着紧密，牙本质小管直径明显减小。每天用HA和nHA刷牙，尤其是后者，显著增加了牙本质片表面的钙和磷含量（P < 0.000）。在铅离子吸附实验中，HA的铅离子吸附率随其浓度增加而降低，最高吸附率为83.01%；nHA的吸附率随其浓度增加直至达到吸附平衡，最高吸附率为98.79%。HA的吸附能力与其浓度之间存在良好的线性关系。
结论
与HA相比，nHA对酸蚀刻牙本质片的表面矿化能力更强，对铅离子的吸附能力也更好。
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