構造用着色レジン複合材のカラーマッチング能力の評価

Evaluation of Color-matching Ability of a Structural Colored Resin Composite.

抄録

臨床的関連性:

構造用着色レジン複合材「オムニクロマ」は優れたカラーマッチング能力を有することが確認されたが、口腔内環境において修復に適した色調条件が得られるように注意する必要がある。

CLINICAL RELEVANCE: Although excellent color-matching ability was confirmed for the structural colored resin composite Omnichroma, care should be taken to ensure that the appropriate chromatic color conditions for restoration are achieved in the oral environment.

サマリー:

目的：本研究では，構造用着色レジン複合材料のカラーマッチング性を評価し，顔料を用いたレジン複合材料と比較した。構造用着色レジン複合材（オムニクロマ[OMC]），スーパーナノ充填レジン複合材（エステライトΣクイック[ELQ]），ナノ充填レジン複合材（フィルテックスプリームウルトラ[FSU]）を使用した。それぞれの樹脂複合体をテフロン製の型に詰め，スライドガラスの下に透明な帯を置いて押し付けた。発光ダイオード硬化装置を用いて，スライドを通して試料に光を照射した。試験片（n=6）の厚さをデジタルノギスで測定した後、蒸留水に移し、37℃で24時間保存した。白黒背景の試料の光学特性の測定は、分光光度計を用いて行った。分光光度計の光源にはD65（CIE D65）を使用した。測定は、各色測定条件で各試料について3回ずつ繰り返し、同一色調の試料3枚の平均値を算出した。一元配置分散分析とTukeyの事後検定を用いた（α=0.05）。人工歯の色との適合性を調べるために，各シェードのコンポジットレジンを虫歯に装着してから色調測定を行った。フレキシブルセンサー付きの分光光度計（CMS-35F S/C）を用いて，L*，a*，b*の値を求めた。OMCの分光反射率曲線は，背景色や試料の厚さにかかわらず，430〜700nmの波長の光を反射することを示していた。ELQの反射率は，550〜580 nmの波長付近で減少した。CIE L*, a*, b*値に対する背景色の影響については，L*値はすべての試験材料が白背景で有意に高い値を示し，OMCは背景色の違いによる影響を最も受けていた。しかし、a*値はELQとFSUでは黒背景の方が白背景よりも有意に高く、OMCでは白背景の方が黒背景よりも有意に高い値を示した。また、b*値は黒背景よりも白背景の方が高く、3製品とも有意に高い値を示し、これらの傾向はELQとFSUで非常に大きかった。結論。OMCの人工歯の色に合わせる能力は，人工歯の色合いや虫歯の深さにかかわらず，許容できる色適合性を示した。しかし，ELQとFSUは，特に虫歯の深さが3.0 mmの場合に，色の適合性が低下した。構造用着色レジン複合材OMCでは，優れた色適合性が確認され，その結果，色差が減少したため，修復物の審美性が向上し，シェードマッチングが容易になり，色の不一致を補うことができた。

SUMMARY: Purpose: The present study evaluated the color-matching ability of a structural colored resin composite to compare it with resin composites employing pigments.Methods and Materials: A structural colored resin composite (Omnichroma [OMC]), a supranano-filled resin composite (Estelite Σ Quick [ELQ]), and a nano-filled resin composite (Filtek Supreme Ultra [FSU]) were used. Each resin composite was packed into a Teflon mold and pressed down with a clear strip under a glass slide. The specimens were light irradiated through the slide with a light-emitting diode curing unit. The thickness of the specimens (n=6) was measured with a digital caliper before being transferred to distilled water and stored at 37°C for 24 hours. The measurements of the optical characteristics of the specimens on a black-and-white background were performed using a spectrophotometer. D65 (CIE D65) was used as a light source for the spectrophotometer. Measurements were repeated three times for each specimen under each color-measurement condition, and average values for three same-shade specimens were calculated. One-way analysis of variance and Tukey post hoc tests were used (α=0.05). To determine its ability to match the color of artificial teeth, each shade of resin composite was placed in a cavity before performing color measurements. Using a spectrophotometer (CMS-35F S/C) with a flexible sensor, L*, a*, and b* values were obtained.Results: The spectral reflectance curve of OMC showed that it reflected light wavelengths from 430-700 nm regardless of the background color and thickness of the specimens. The percentage of reflectance of ELQ decreased near wavelengths of 550-580 nm. Regarding the influence of background color on CIE L*, a*, b* values, the L* level showed significantly higher values for all tested materials with white backgrounds, and OMC was most affected by the difference in background color. However, a* values of ELQ and FSU were significantly higher with a black background than with a white background, and OMC showed a significantly higher value with a white background than with a black background. The b* values were higher with a white background than with a black background and were significantly higher for all three products, and these tendencies were much greater for ELQ and FSU.Conclusions: The ability of OMC to match the color of artificial teeth showed acceptable color compatibility, regardless of the shade of the artificial teeth and the depth of the cavity. However, ELQ and FSU showed reduced color compatibility, especially for a cavity depth of 3.0 mm. Excellent color matching ability was confirmed for the structural colored resin composite OMC, resulting in reduced color differences and therefore improving the esthetic appearance of the restoration, simplifying shade matching, and compensating for any color mismatch.