A novel approach for improvement of the interfacial binding of ceramics for dental materials: Chemical treatment and oxygen plasma etching

Dental ceramic is one of the most widely used materials in the dental industry because of its extensive use in resin‐bonded restorations and porcelain repair systems. In this study, two approaches were applied to dental ceramic surfaces for improvement in the wettability and surface energy of the effective resin–ceramic interfacial binding. One group of dental ceramics was treated by glow discharge with oxygen at a discharge power of 20 W and for an exposure time of 15 min. The other group was dipped onto hydrofluoric acid (HF) solution. Then, the samples were washed with distilled water and dried at the room temperature before the oxygen plasma treatment. The effectiveness of the two approaches was compared by means of changes in the surface wettability and polarity as measured by both the sessile drop and captive bubble techniques. Oxygen plasma treatment increased the surface wettability, but a greater increase was found with HF etching before the oxygen plasma treatment. This result was demonstrated by the decrease in the static contact angle as measured by the sessile drop technique (53.6 ± 4.19 to 27.7 ± 3.30). In addition, with the combination of the prechemical treatment with HF and the oxygen plasma treatment, the polarity increased more dramatically (0.706 ± 0.013 to 0.845 ± 0.008). The surface chemical composition and physical morphology were investigated by X‐ray photoelectron spectroscopy and scanning electron microscopy. Furthermore, the HF etching before oxygen plasma treatment was found to improve the shear bond strength, and it was significantly stronger than that of the groups treated with oxygen only for the resin composite materials (p < 0.05). This two‐step treatment could be a new approach for the activation of dental ceramic discs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

含乙氧甲酰甲氨基咪唑杯[4]芳烃的合成及其水相体系中对Al3+和Ag+的荧光识别

该文以二溴丁氧基杯[4]芳烃和取代的1H-咪唑为原料合成了乙氧甲酰甲氨基咪唑杯[4]芳烃(M),采用红外、核磁、质谱对所合成化合物进行了结构表征;采用紫外吸收光谱和荧光发射光谱,在体积比为3∶7的甲醇/水混合溶液(Tris-HCl缓冲溶液,pH=6.5)中考察了M对常见金属离子的识别性能。结果发现,化合物M以1∶1的络合比对Al~(3+)进行选择性识别,且识别行为不受其他常见金属离子的干扰;化合物M以1∶2的络合比与Ag~+络合,当Al~(3+)作为干扰离子且浓度高于Ag~+时,对M与Ag~+的识别产生干扰。即,当Al~(3+)和Ag~+同时存在时,化合物M与Al~(3+)具有更好的识别选择性。