光重合型コンポジットレジンの光透過性と色の関係

抄録

In modern composite resin restoration, material properties are important to give restorations natural colors and esthetics appearance. In recent years, based on the concept of minimal intervention (MI), light-cured composite resins have been frequently used to restore teeth without damaging healthy dentin with good esthetic results. However, it is very difficult to match colors in composite resin restorations. At present, a range of color shades is available for light-cured composite resins, but when restoring teeth with stained dentin, the color of composite resin selected using a shade guide does not always match the color of the surrounding dentin. This is because colors vary depending on composite resin thickness and dentine color. With regard to color compatibility of composite resins, both color and material translucency play important roles. In recent years, composite resins have been developed by taking into account the color and optical transparency of natural tooth enamel, and it is generally accepted that the appearance of translucent materials involves a complex relationship between various reflected lights. In other words, when mixing filler and matrix resin with a composite resin, light is diffused and reflected by surrounding dentin and colors. In the present study, composite resins with four different filler types, including a nano filler, were used in order to determine the effects of sample thickness, background color and filler morphology on color. The following conclusions were drawn: 1. When sample thickness was low, the spectral reflectivity of white and black backgrounds overlapped in the low wavelength region, and when sample thickness was high, spectral reflectivity was the same value in the high wavelength region. 2. Based on CIELAB, when thickness was low, hybrid composite resin with large filler and nano filler particles was less affected by L* value when compared when composite resin with small filler particles. 3. The contrast ratio of hybrid composite resin with large filler and nano filler particles was higher than that for composite resin with small filler particles when thickness was low. 4. For all samples, the greater the thickness, the lower the TP value and the smaller the rate of decrease in TP value.