最近開発された象牙質接着システムの象牙質接着強さに及ぼす環境条件の影響

Influence of environmental conditions on dentin bond strengths of recently developed dentin bonding systems.

抄録

最近開発された数種の象牙質接着システムの接着強さに及ぼす温度と相対湿度（RH）の影響について検討した．(A)25+/-0.5℃，50+/-5%RH，(B)25+/-0.5℃，80+/-5%RH，(C)25+/-0.5℃，95+/-5%RH，(D)37+/-0.5℃，50+/-5%RH，(E)37+/-0.5℃，80+/-5%RH，(F)37+/-0.5℃，95+/-5%RHの6つの環境条件を用いた．ウシの下顎切歯を自己硬化型レジンに装着し、象牙質を露出させるため、顔面を湿潤#600 SiCペーパーで研磨した。各製造業者の指示に従って歯面を処理した後、接着剤を塗布し、その後、象牙質表面に設置した型にレジン組成物を凝縮させた。各群15本の試験片を37℃の蒸留水中で24時間保存した後、クロスヘッドスピード1.0mm/minでせん断試験を行った。統計解析は、二元配置分散分析にTukeyの検定を加えて行った（P<0.05）。象牙質接着強さは相対湿度の上昇とともに低下したが、環境温度の影響は受けなかった。ワンボトル接着システムは湿潤象牙質表面を必要とするにもかかわらず、その接着強さは環境湿度の上昇に影響される。

A study was conducted to investigate the influence of temperature and relative humidity (RH) on the bond strengths of several recently developed dentin bonding systems. Six environmental conditions, (A) 25+/-0.5 degrees C, 50+/-5% RH, (B) 25+/-0.5 degrees C, 80+/-5% RH, (C) 25+/-0.5 degrees C, 95+/-5 % RH, (D) 37+/-0.5 degrees C, 50 +/-5 % RH, (E) 37+/-0.5 degrees C, 80+/-5% RH, (F) 37+/-0.5 degrees C, 95+/-5 % RH were used. Bovine mandibular incisors were mounted in self-curing resin and the facial surfaces were ground on wet #600 SiC paper to expose the dentin. After the tooth surface had been treated according to each manufacturer's instructions, adhesives were applied, followed by condensation of resin composites into a mold placed on the dentin surface. Fifteen specimens per group were stored in distilled water at 37 degrees C for 24 h, and then shear-tested at a cross-head speed of 1.0 mm/min. Statistical analysis was carried out with two-way ANOVA followed by Tukey's test (P<0.05). Dentin bond strengths decreased with increasing relative humidity but were not influenced by environmental temperature. Even though one-bottle adhesive systems require a wet dentin surface, their bond strengths are affected by an increase in environmental humidity.