Hydroxyapatite nanorods as novel fillers for improving the properties of dental adhesives: Synthesis and application
Hydroxyapatite nanorods as novel fillers for improving the properties of dental adhesives: Synthesis and application
复制标题
DOI：
10.1016/j.dental.2010.01.005
复制
发表时间：
2010-05-01
期刊：
影响因子：
5
通讯作者：
Khanlar, Leila Nasiri
中科院分区：
文献类型：
--
作者：
Sadat-Shojai, Mehdi;Atai, Mohammad;Khanlar, Leila Nasiri
目标.本研究评估了以下假设：将水热法合成的具有高结晶度和高纵横比的纤维状羟基磷灰石纳米颗粒掺入实验性乙醇基单瓶牙本质粘合剂中，改善了粘合剂层的机械性能，并相应地增加了与牙本质的粘结强度。采用简单的水热法合成了羟基磷灰石纳米棒。首先，将含HPO 42的溶液滴加到含Ca 2+的溶液中，同时将Ca/P的摩尔比调节为1.67。然后将HAp前体在200 ℃下水热处理60小时。使用XRD、FTIR、SEM、TEM和EDXA对所得粉末进行表征。将合成的HAp纳米棒加入到实验性的一瓶牙本质粘合剂中，然后对填充的粘合剂进行表征。评价了7种含不同纳米棒含量的粘结剂体系的径向拉伸强度、弯曲强度、弯曲模量和与人前磨牙牙本质的微剪切粘结强度。使用EDX-绘图确定填料的分布。还使用刮擦技术评价固化深度。此外，在微剪切试验后，使用SEM观察断裂横截面以确定所涉及的失效模式。使用分离分析仪和zeta电位测量研究了胶体稳定性。数据采用单因素方差分析和Tukey检验进行分析。结果证实了合成的HAp纳米棒的高纯度、高结晶度和高纵横比。当纳米棒含量为0.2- 0.5wt.%时，HAp纳米棒被掺入（p < 0.05）。在挠曲试验中观察到类似的趋势，在填料含量为0.2-0.5重量%时提供更高的挠曲强度而弯曲模量保持不变。最高的微剪切粘结强度也获得了0.2重量%填料含量（P < 0.05）。新型胶粘剂体系性能的改善可能是由于纳米棒的高结晶度和高长径比。脱粘表面的扫描电镜观察显示，大多数标本显示从粘接剂-牙本质界面的粘接失败。能量色散X射线（EDX）成像证实了纳米棒在粘合剂基质中的均匀分布。胶体稳定性研究表明，合成的羟基磷灰石纳米棒在牙科粘接液中具有较高的胶体稳定性。事实上，纳米棒分散良好，并通过zeta电位测量证实其高表面电荷防止聚集。羟基磷灰石基复合材料已显示出良好的生物活性。然而，关于纳米羟基磷灰石对牙科材料，特别是牙本质粘接剂性能的影响的认识还不够。本文提出的含纳米棒的粘合剂系统可能被认为在牙科诊所中具有实际应用。(C)2010年牙科材料学院。由爱思唯尔有限公司出版。保留所有权利。
Objectives. This study evaluates the hypothesis that the incorporation of fibrous hydroxyapatite nanoparticles with high crystallinity and high aspect ratio, synthesized by hydrothermal method, into an experimental ethanol-based one-bottle dentin adhesive, improves the mechanical properties of the adhesive layer, and accordingly increases the bond strength to dentin.Methods. Hydroxyapatite nanorods were synthesized using a simple hydrothermal procedure. First, the HPO42-containing solution was added drop-wise into the Ca2+-containing solution while the molar ratio of Ca/P was adjusted at 1.67. The HAp precursor was then treated hydrothermally at 200 degrees C for 60 h. The resulting powder was characterized using XRD, FTIR, SEM, TEM, and EDXA. The synthesized HAp nanorods were added to an experimental one-bottle dentin adhesive followed by the characterization of the filled adhesive. The diametral tensile strength, flexural strength, flexural modulus, and the microshear bond strength to the dentin of human premolars of seven adhesive systems containing different nanorod contents were evaluated. The distribution of the filler was determined using EDX-mapping. The depth of cure was also evaluated using scraping technique. Moreover, after microshear testing, the fracture cross-section was observed using SEM to determine the mode of failure involved. The colloidal stability was studied using a separation analyzer and also zeta potential measurement. Data were analyzed using one-way analysis of variance followed by the Tukey test.Results. The results confirmed the high purity, high crystallinity, and high aspect ratio of synthesized HAp nanorods. The diametral tensile strength of nanorod containing adhesive system appeared to increase when 0.2-0.5 wt.% HAp nanorods were incorporated (p < 0.05). A similar trend was observed in the flexural test providing higher flexural strength at filler contents of 0.2-0.5 wt.% while flexural modulus remained unchanged. The highest microshear bond strength was also obtained at 0.2 wt.% filler content ( p < 0.05). The improved properties of the new adhesive system might be due to the high crystallinity and high aspect ratio of the nanorods. SEM observation of debonded surfaces revealed that most specimens showed an adhesive failure from the adhesive-dentin interface. Energy dispersive X-ray (EDX) mapping confirmed the uniform distribution of nanorods in the adhesive matrix. The colloidal stability studies indicated that synthesized hydroxyapatite nanorods have high colloidal stability in the dental adhesive solution. Indeed, the nanorods are well dispersed and protected from aggregation by their high surface charge confirmed by zeta potential measurement.Significance. Hydroxyapatite-based composites have shown promising bioactivity. However, the knowledge about the influence of the nano-sized HAp on the properties of the dental materials, especially dentin bonding adhesives, is yet insufficient. The nanorod containing adhesive system presented here might be considered to have practical applications in dental clinics. (C) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.