汚染された象牙質に対する自己接着性レジン合着セメントの接着強さに及ぼす歯牙処理洗浄プロトコルの影響

The effects of tooth preparation cleansing protocols on the bond strength of self-adhesive resin luting cement to contaminated dentin.

抄録

このin vitro研究では，象牙質の表面汚染を除去するために4つの異なる手法を用いた後の自己接着性合着セメントの接着強さを評価しました．抜歯したヒトの大臼歯を平らにして象牙質を露出させ，歯冠を作製しました．アクリル製の仮歯を作製し，仮着用セメントを用いて装着した．試料は，室温，相対湿度100%で7日間保管した。仮歯を除去した後，無作為に4群に分け，余分な仮歯を(1)ハンドインスツルメント（ショベルカー），(2)軽石粉と水を混合したプロフィー，(3)40psiで27μmの粒径の酸化アルミ研磨，(4)40psiで50μmの粒径の酸化アルミ研磨で除去した．ランダムに選んだ試料のSEMおよびEDS分析を用いて，歯の表面の微細構造形態を評価し，残留物質を検出した。セラミックスは9.5%フッ化水素酸エッチングで処理し，自己接着性レジンセメント（RelyX Unicem，3M ESPE）で接着する前に，準備した象牙質にシラン処理を施した．剪断接着強さは，クロスヘッドの速度を0.5mm/分として測定した。結果は一元配置のANOVAで分析し，その後Tukeyのテストを行った．酸化アルミニウム粒子を用いた象牙質の粒子摩耗処理は接着強さの値が最も高く，手工具による掘削処理は最も低かった（p < 0.05）。酸化アルミニウムの粒子径は，40psiでの接着強さに有意な影響を与えなかった．最終的なセメント注入前の機械的な洗浄方法として，低圧・小粒径の研磨処理を施した象牙質を使用することで，ユーゲノールを含む一時的なセメントを使用した後の自己接着性樹脂注入用セメントの象牙質への接着強さが向上した．

This in vitro study evaluated the bond strength of a self-adhesive luting cement after using four different techniques to remove surface contamination on dentin. Extracted human molars were flattened to expose the dentin surface and prepared for full crown preparation. Acrylic temporary crowns were fabricated and placed using temporary cement. The specimens were stored at room temperature with 100% relative humidity for seven days. Following removal of the temporary crowns, the specimens were randomly divided into four groups, and excess provisional cement was removed with (1) a hand instrument (excavator), (2) prophy with a mixture of flour pumice and water (3) aluminous oxide abrasion with a particle size of 27 microm at 40 psi and (4) aluminous oxide abrasion with a particle size of 50 microm at 40 psi. The microstructure morphology of the tooth surface was evaluated and residual materials were detected using SEM and EDS analysis of randomly selected specimens. The ceramics were treated with 9.5% hydrofluoric acid-etch and silanized to the prepared dentin prior to cementing with self-adhesive resin cement (RelyX Unicem, 3M ESPE). The shear bond strength was determined at a crosshead speed of 0.5 mm/minute. The results were analyzed with one-way ANOVA, followed by Tukey's test. Particle abrasion treatment of dentin with an aluminous oxide particle provided the highest values of bond strength, while hand instrument excavation was the lowest (p < 0.05). Aluminous oxide particle size did not significantly influence the bond strength at 40 psi. The use of low pressure and small particle abrasion treated dentin as a mechanical cleansing protocol prior to definitive cementation increased the bond strength of self-adhesive resin-luting cement to dentin following eugenol-containing temporary cement.