不同pH值和F^-浓度人工唾液对钛/瓷结合的影响

研究了不同pH值和F^-浓度人工唾液对钛/瓷结合性能的影响。将实验室制备的钛瓷粉分层烧结于钛片上,浸泡于37℃,pH2.7、pH7.0/F^-100μg·mL^(-1)与pH2.7/F100μg·mL^(-1)的人工唾液中,测量了浸泡7d和30d试件的三点弯曲结合强度,应用扫描电镜观察了瓷剥脱后钛表面的形貌,并进行了EDX分析。结果显示:pH2.7/F^-100μg·mL^(-1)组试件的钛/瓷结合强度明显低于未浸泡组,其余各组与未浸泡组相比无显著差异。研究结果提示:酸性环境中,F^-的存在可使钛/瓷结合强度降低,而酸性环境和低浓度的F^-环境对钛/瓷结合强度则没有明显影响,口腔内有钛瓷修复体的患者应慎用含氟口腔产品。

复合纳米金膜技术增强牙科钛瓷结合的基础研究

目的利用离子多层自组装技术在纯钛表面沉积复合纳米金膜并烧结专用钛瓷粉,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,沉积纳米金膜为实验组(AuS);非沉积纳米金膜为对照组(S),每组10个钛瓷标准试件。运用场发射扫描电镜(FE-SEM)观察钛试件沉积纳米金膜后的表面形态以及钛瓷结合界面的微观形貌。三点弯曲法测定钛瓷结合强度,并进行统计学分析。体视显微镜观察钛瓷界面的断裂模式。电子探针(EMP)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。FE-SEM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;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。EMP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,在粘接瓷底部呈点状弥散。结论在本研究条件下,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。

Three-point bending performance of a new aluminum foam composite structure

A new composite structure based on aluminum foam sandwich and fiber metal laminate was proposed. A layer of glass fiber was provided at the interface between the metal panel and the aluminum foam core in this composite structure, using adhesive technology to bond the materials together by organic glue in the sequence of metal panel, glass fiber, aluminum foam core, glass fiber and metal panel. The experimental results show that the new composite structure has an improved comprehensive performance compared with the traditional aluminum foam sandwiches. The optimized parameters for the fabrication of the new aluminum foam composite structure with best bending strength were obtained. The epoxy resin and low porosity aluminum foams are preferred, the thickness of aluminum sheets should be at least 1.5 mm, and the type of glass fiber has little effect on the bending strength. The main failure modes of the new composite structures with two types of glues were discussed.