【作者】 李宁；

【导师】 骆小平；

【作者基本信息】 南京大学 ， 口腔医学， 2014， 硕士

【摘要】 钛及钛合金由于良好的抗腐蚀性、极佳的生物安全性以及优异的力学性能,是现今广泛应用于牙科以及其他医疗领域的潜力材料之一。近年来,由于贵金属价格较高以及人们对于普通含镍金属的生物安全性的质疑,钛及钛合金被普遍认为可能成为烤瓷修复体金属基底冠的替代材料,因为它不仅结合了金属的强度和瓷的美学性能、避免了氧化锆全瓷支架在后牙区因咬合力过大而发生折裂的风险,而且可防止在口腔内使用不同金属而产生的电化学腐蚀。然而,由于纯钛金属在高温下化学活动性增强,极易发生氧化,并产生相变,导致钛-瓷结合力的耐久性不足,限制了钛-瓷修复体的临床使用。研究表明,纯钛铸造和烤瓷烧结过程中的高温环境都会造成钛表面的过度氧化,形成过厚的硬且松脆的氧化膜层,对此氧化膜层的控制正是提高钛-瓷结合强度的关键点。为了控制烤瓷烧结过程中钛表面氧化层的形成,许多种元素被用作钛表面涂层材料来阻止烤瓷烧结过程中氧气向钛表面的扩散,以抑制氧化膜层的形成,主要包括Si3N4涂层、SiO2涂层、Cr涂层以及TiN涂层,也有研究通过使用毛刷涂覆金膏、金离子磁控溅射的方法在纯钛表面引入金中间涂层,结果表明纯钛表面金涂层可以抑制钛表面过度氧化反应的发生,使钛-瓷结合力得到了增强,但以上操作的技术敏感性均较高。离子自组装多层技术(Ionic Self-assembled Multilayers, ISAM)是一种崭新的成膜工艺,可以利用离子间的静电相互作用力层层自组装形成薄膜,它所能应用的成膜基底的种类及形状几乎不受限制,例如玻璃、硅片、金属等作为成膜基底,此技术为钛瓷间引入中间涂层提供了一个新的研究思路。[目的]本研究旨在利用离子多层自组装技术(ISAM)在纯钛表面沉积复合纳米金膜并烧结专用钛瓷粉Super porcelain Ti-22,探讨该技术对钛-瓷之间结合强度的影响。[方法]根据ISO 9693要求制备预成纯钛试件20个,根据是否沉积复合纳米金膜进行分组(沉积纳米金膜：AuS；非沉积纳米金膜：S),每组10个钛-瓷标准试件。场发射扫描电镜观察钛试件沉积纳米金膜后的表面形态,烤瓷烧结Super porcelain Ti-22后进一步观察钛-瓷结合界面的微观形貌。三点弯曲实验测定钛-瓷结合强度,并进行统计学分析。体视显微镜观察确定钛-瓷试件的断裂模式。电子探针检测结合界面上Au元素的分布情况。[结果]AuS组的钛瓷结合强度(36.24±3.64 MPa)明显高于S组的钛瓷结合强度(30.78±3.83 MPa,p<0.05)。场发射扫描电镜观察显示钛表面沉积纳米金颗粒后形成了均匀、致密的复合纳米金膜。电镜观察结合界面显示,AuS组钛-瓷结合界面连续而紧密,体视显微镜观察断裂模式以混合断裂为主；而对照组钛-瓷结合界面可见明显的裂隙,偶有气泡,断裂模式以界面断裂为主。电子探针检测结果显示结合界面上可见Au元素分布,纳米金颗粒在烧结过程中团聚成簇后沿钛-瓷结合界面呈带形分布、点状弥散在粘结瓷底部。[结论]在本实验研究条件下,纯钛表面沉积复合纳米金膜可显著提高Super porcelain Ti-22专用钛瓷粉与预成纯钛试件之间的结合强度。更多还原

【Abstract】 Nowdays, titanium and titanium alloys are widely used in dentistry and other medical fields due to their good corrosion resistance, excellent biocompatibility and superior mechanical properties, and also because of the higher prices of noble metals and much more concerns about biosecurity of nickel-containing metals, titanium and titanium alloys are widely considered likely to become to be substitute of metal ceramic restorations. Besides the esthetics, the excellent strength of PFT can avoid the risk of the the zirconia ceramic framework fracture caused by the excessive occlusal force in the posterior teeth region. Moreover, electrochemical corrosion between different metals can be avoided in oral environment. However, oxidation and phase transformation of pure titanium easily occur under high-temperature conditions, which leads to the insufficient durability of the Ti-ceramic bond and limits the clinical application of the PFT restorations. So most of the research in recent years are focused on how to control the formation of the oxide layer in sintering process, consequently numerous elements have been used as surface coatings to prevent excessive titanium oxidation during the firing stage. It has been reported that coating titanium surfaces with Si3N4、 SiO2、Cr and TiN lowers its rate of oxidation, similar results have been obtained by coating the titanium with gold paste and magnetron sputtering with gold ions. Though both the methods can prevent over-oxidation on the titanium surface and improve Ti-ceramic bond strength, but they are very sensitive to the clinical coating technique. Ionic self-assembled multilayer(ISAM) technique is a very new technology that can use electrostatic interactions between different ions to form a thin film, and the type of film base is unlimited, such as glass, silicon films, metal, etc. So this technique provides a new research idea for introducing a intermediate coating between titanium and ceramic.ObjectiveTo investigate the effect of composite nano-gold films deposited on the pure titanium by ionic self-assembled mutilayers (ISAM) technique on the adhesion of porcelain to titanium.MethodsTwenty pure titanium specimens were prepared by machining procedure in rectangular shape according to ISO 9693 to make two groups of each set (n=10). All specimens were sandblasted with 150 μm Al2O3 particles at the pressure of 0.2 MPa. Then one group of the specimens were deposited composite nano-gold films, and the other serve as a control group. A layer of porcelain was built up onto the titanium strips of both groups with a conventional technique. Field emission scanning electron microscope (FE-SEM) was used to observe the surface morphology of titanium specimen after depositing composite nano-gold films, and further observe the microstructure of the interface between titanium and porcelain after sintered. Optical Stereomicroscope was used to characterize the titanium-porcelains adhesion and determine the mode of failure after three-point bending test was performed. The distribution of the Au element on the interface of titanium-porcelain was detected by electron microprobe (EMP).ResultsThe adhesion of nano-gold film deposited group was significantly higher than those of the undeposited group [(36.24±3.64 MPa) and (30.78±3.83 MPa), p<0.05]. FE-SEM illustrated that the surface of the nano-gold deposited group formed a uniform, dense composite nano-gold film. Stereomicroscope and SEM images showed that composite nano-gold films enhanced the bond strength between porcelain and titanium. Small, white spots of gold particles could be detected along the titanium-porcelain bonding interface by electron microprobe (EMP).ConclusionsThe bending strength between porcelain and titanium was significantly improved when titanium was deposited with composite nano-gold films.更多还原