Maesako Mayumi, Kishimoto Takafumi, Tomoda Shigetaka, Horie Taku, Yamada Mitsuyoshi, Iwawaki Rika, Odagiri Yukari, Sakuma Keiko, Inoue Kazuho, Takeguchi Ayumi, Suzuki Miki, Mitani Akio, Fujitani Morioki
Department of Operative Dentistry, School of Dentistry, Aichi Gakuin University, Nagoya 464-8651, Japan.
Department of Periodontology, School of Dentistry, Aichi Gakuin University, Nagoya 464-8651, Japan.
Materials (Basel). 2021 Nov 28;14(23):7280. doi: 10.3390/ma14237280.
Resin composites employing structural coloration have recently been developed. These resins match to various tooth shades despite being a single paste. To accomplish this, the filler and base resin are tightly bonded, which is thought to provide excellent discoloration resistance. Here, we investigated the surface properties of one of these resins, including the discoloration of the repolished surface. We developed an innovative in vitro method to adjust the repolished surface, in which structural degradation is removed according to scanning electron microscopy (SEM) observation rather than by the naked eye. The resin samples (20 mm (length) × 10 mm (width) × 4 mm (depth)) were manufactured using this resin material. After accelerated aging of the resin by alkaline degradation, the resin was repolished and the discoloration (ΔE*ab), surface roughness (the arithmetic mean roughness (Ra)), and glossiness (the 60° specular) were measured. SEM observation showed that the appearance of the bond between the organic composite filler and base resin on the repolished surface was different from that on the mirror-polished surface. This revealed that according to our in vitro method it was difficult to make the repolished surface structurally identical to the mirror-polished surface. Among the properties of the repolished surface, the degree of discoloration did not change despite the rougher and less glossy surface. It can be concluded that the factors that induce discoloration in this resin composite are independent of the surface roughness and glossiness.
最近已开发出采用结构显色的树脂复合材料。这些树脂尽管是单一组分，但能匹配各种牙齿颜色。为实现这一点，填料和基础树脂紧密结合，这被认为可提供出色的抗变色性能。在此，我们研究了其中一种树脂的表面特性，包括重新抛光表面的变色情况。我们开发了一种创新的体外方法来调整重新抛光表面，该方法根据扫描电子显微镜（SEM）观察而非肉眼观察去除结构降解。使用这种树脂材料制作树脂样本（20毫米（长）×10毫米（宽）×4毫米（深））。通过碱性降解对树脂进行加速老化后，对树脂进行重新抛光，并测量变色程度（ΔE*ab）、表面粗糙度（算术平均粗糙度（Ra））和光泽度（60°镜面光泽度）。SEM观察表明，重新抛光表面上有机复合填料与基础树脂之间的结合外观与镜面抛光表面不同。这表明根据我们的体外方法，很难使重新抛光表面在结构上与镜面抛光表面相同。在重新抛光表面的特性中，尽管表面更粗糙且光泽度更低，但变色程度并未改变。可以得出结论，这种树脂复合材料中引起变色的因素与表面粗糙度和光泽度无关。
