Hiraba Haruto, Koizumi Hiroyasu, Kodaira Akihisa, Nogawa Hiroshi, Yoneyama Takayuki, Matsumura Hideo
Department of Fixed Prosthodontics, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
Division of Advanced Dental Treatment, Dental Research Center, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
Materials (Basel). 2020 May 1;13(9):2092. doi: 10.3390/ma13092092.
The aim of this study was to clarify the influence of the copper surfaces changed from Cu or CuO to CuO on the bonding strength of resin with organic sulfur compounds. The disk-shaped specimens ( = 44) of copper were wet-ground. Half of the specimens were heated at 400 °C for 4 min in an electric furnace (HT: heated). Half of the specimens were not heated (UH: unheated). The specimens were further divided into two groups. Each group was primed by 6-methacryloyloxyhexyl 2-thiouracil-5-carboxylate (MTU-6) or unprimed ( = 11). A statistical analysis of the results of shear bond strength testing was performed, and the failure mode of the bonded areas was classified with an optical microscope. Two types of specimen surface (UH or HT) were analyzed chemically using X-ray photoelectron spectroscopy (XPS). When primed with MTU-6, unheated Cu (28.3 MPa) showed greater bond strength than heated (19.1 MPa). When unprimed, heated Cu (4.1 MPa) showed greater bond strength than unheated (2.3 MPa). The results of the debonded surfaces observation showed that only the UH-MTU-6 group demonstrated a combination of adhesive and cohesive failures in all specimens. The XPS results showed that the surface of copper changed from Cu or CuO to CuO when HT. These results confirmed that it is necessary to take care of the copper oxide contained in noble metal alloys when using organic sulfur compounds for adhesion.
本研究的目的是阐明铜表面从Cu或CuO转变为CuO对树脂与有机硫化合物粘结强度的影响。对圆盘状铜试样（n = 44）进行湿磨。其中一半试样在电炉中于400℃加热4分钟（HT：加热）。另一半试样未加热（UH：未加热）。将试样进一步分为两组。每组分别用6-甲基丙烯酰氧基己基2-硫尿嘧啶-5-羧酸盐（MTU-6）处理或未处理（n = 11）。对剪切粘结强度测试结果进行统计分析，并用光学显微镜对粘结区域的失效模式进行分类。使用X射线光电子能谱（XPS）对两种类型的试样表面（UH或HT）进行化学分析。用MTU-6处理时，未加热的Cu（28.3 MPa）显示出比加热后的Cu（19.1 MPa）更高的粘结强度。未处理时，加热后的Cu（4.1 MPa）显示出比未加热的Cu（2.3 MPa）更高的粘结强度。脱粘表面观察结果表明，只有UH-MTU-6组在所有试样中都表现出粘结和内聚破坏的组合。XPS结果表明，加热时铜表面从Cu或CuO转变为CuO。这些结果证实，在使用有机硫化合物进行粘结时，必须注意贵金属合金中所含的氧化铜。
