Yamaji Ayumi, Koga Kensaku, Tsujimoto Akimasa, Shimizu Yusuke, Tsubota Keishi, Takamizawa Toshiki, Miyazaki Masashi
Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
Eur J Oral Sci. 2013 Oct;121(5):497-503. doi: 10.1111/eos.12077. Epub 2013 Aug 17.
This study evaluated the influence of an oxygen-inhibited layer on the surface free energies of three single-step self-etch adhesives and on the bond strength of chemical-cured resin. Adhesives were applied to bovine dentin and light irradiated, and the oxygen-inhibited layer was either retained or removed. Surface free energies were determined by measuring the contact angles of test liquids placed on the cured adhesives. Dentin bond strengths of chemical-cured resin with and without the oxygen-inhibited layer were measured. Ultrastructural observation of the restorative-dentin interface was made by scanning electron microscopy. For all surfaces, values of the estimated surface tension component, Lifshitz-Van der Waals force (γS(LW)), were relatively constant. Values for the Lewis acid (γS(+)) component increased slightly when the oxygen-inhibited layer was removed, whereas those of the Lewis base (γS(-)) component decreased significantly. The bond strength of the chemical-cured resin composite was significantly higher in specimens without an oxygen-inhibited layer (7.6-8.0 MPa) than in those with an oxygen-inhibited layer (4.8-5.2 MPa). Small gaps between adhesive and resin composite were found for the group with an oxygen-inhibited layer. These results indicate that the absence of an oxygen-inhibited layer in single-step self-etch adhesives promotes higher dentin bond strength of the chemical-cured resin.
本研究评估了氧抑制层对三种单步自酸蚀粘结剂表面自由能以及化学固化树脂粘结强度的影响。将粘结剂应用于牛牙本质并进行光照，然后保留或去除氧抑制层。通过测量放置在固化粘结剂上的测试液体的接触角来测定表面自由能。测量了有无氧抑制层的化学固化树脂与牙本质的粘结强度。通过扫描电子显微镜对修复体 - 牙本质界面进行超微结构观察。对于所有表面，估计的表面张力分量，即 Lifshitz - 范德华力（γS(LW)）的值相对恒定。当去除氧抑制层时，路易斯酸（γS(+)）分量的值略有增加，而路易斯碱（γS(-)）分量的值则显著降低。无氧抑制层的标本中化学固化树脂复合材料的粘结强度（7.6 - 8.0 MPa）明显高于有氧抑制层的标本（4.8 - 5.2 MPa）。对于有氧抑制层的组，在粘结剂和树脂复合材料之间发现了小间隙。这些结果表明，单步自酸蚀粘结剂中无氧抑制层可提高化学固化树脂与牙本质的粘结强度。
