Nakabayashi N, Takarada K
Institute for Medical and Dental Engineering, Tokyo Medical and Dental University.
Dent Mater. 1992 Mar;8(2):125-30. doi: 10.1016/0109-5641(92)90067-m.
The present study investigated the effectiveness of treating dentin with 2-hydroxyethyl methacrylate (HEMA) prior to application of an adhesive resin. The adhesive resin was 5% 4-methacryloxyethyl trimellitate anhydride (4-META) in methyl methacrylate (MMA) combined with poly-MMA powder. Polymerization of this resin was initiated by tri-n-butyl borane (TBB). Bovine dentin samples were ground with 600-grit Carbimet paper discs, and demineralized with either an aqueous solution of 10% citric acid/3% ferric chloride (10-3) or an aqueous solution of 10% citric acid (10-0). Improved bond strengths were achieved with HEMA treatment of bovine dentin samples, and improvement of bond strengths was dependent upon the time period of HEMA application. Scanning electron microscope (SEM) examination revealed the formation of a transitional zone of resin-reinforced dentin, termed the "hybrid" layer, in those specimens receiving 10-3 pre-treatment. The adhesive resin impregnated the exposed collagen bundles with which it entangled to create the "hybrid", essential in the attainment of high tensile bond strengths. Specimens pre-treated with 10-0 did not readily form "hybrid" layers. However, if HEMA application followed the 10-0 pre-treatment, "hybrids" were demonstrated on SEM, and bond strength increased to 13 MPa. The ferric ions in the 10-3 effectively improved the diffusivity of dentinal substrates, as did HEMA. This study indicates that HEMA applied to dentinal substrates enhances monomer diffusion and entanglement with dentinal components, and facilitates the formation of a "hybrid" layer.
本研究调查了在应用粘结树脂之前用甲基丙烯酸2-羟乙酯（HEMA）处理牙本质的效果。粘结树脂是5%的偏苯三酸三（4-甲基丙烯酰氧乙基）酯（4-META）溶于甲基丙烯酸甲酯（MMA）并与聚甲基丙烯酸甲酯粉末混合而成。该树脂的聚合由三正丁基硼（TBB）引发。牛牙本质样本用600目碳化硅砂纸盘研磨，并用10%柠檬酸/3%氯化铁水溶液（10-3）或10%柠檬酸水溶液（10-0）脱矿。对牛牙本质样本进行HEMA处理可提高粘结强度，且粘结强度的提高取决于HEMA处理的时间。扫描电子显微镜（SEM）检查显示，在接受10-3预处理的样本中形成了树脂增强牙本质的过渡区，称为“混合”层。粘结树脂浸渍暴露的胶原束并与之缠结形成“混合”层，这对于获得高拉伸粘结强度至关重要。用10-0预处理的样本不易形成“混合”层。然而，如果在10-0预处理后应用HEMA，SEM显示有“混合”层，且粘结强度增加到13MPa。10-3中的铁离子与HEMA一样有效地提高了牙本质底物的扩散性。本研究表明，应用于牙本质底物的HEMA可增强单体扩散以及与牙本质成分的缠结，并促进“混合”层的形成。
