Saikaew Pipop, Matsumoto Mariko, Sattabanasuk Vanthana, Harnirattisai Choltacha, Carvalho Ricardo M, Sano Hidehiko
Department of Operative Dentistry and Endodontics, Faculty of Dentistry, Mahidol University, Bangkok, Thailand.
Department of Restorative Dentistry, Faculty of Dentistry, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan.
Eur J Oral Sci. 2020 Jun;128(3):246-254. doi: 10.1111/eos.12698. Epub 2020 May 12.
Using transmission electron microscopy (TEM), this study investigated the characteristics of smear layers after preparation of dentin surfaces using different methods. In addition, this study analyzed, using scanning electron microscopy (SEM), the interactions of smear layers with the various acidic agents used subsequently to treat the dentin surface. Mid-coronal dentin surfaces were prepared according to one of five instrumentation methods: fracture; grinding with carbide bur; grinding with regular-grit diamond bur; grinding with superfine-grit diamond bur; or grinding with 600-grit silicon carbide (SiC) abrasive paper. Then, each prepared dentin surface was further divided into control (no further treatment) or treatment with one of the following agents: phosphoric acid solution (PAS); phosphoric acid gel (PAG); Clearfil SE Bond 2 Primer (SE2); or Scotchbond Universal Adhesive (SBU). Longitudinal ultra-thin sections were made for TEM observations. Dentin discs, representing each surface preparation and treatment method described above, were created, and the morphology was examined by SEM. The TEM results revealed differences in thickness and denseness of the smear layer, according to the different methods of instrumentation used to prepare the dentin surface. The two forms of phosphoric acid completely removed the smear layer in all groups. Agglomerated silica particles were observed on the top of the collagen layer after etching with PAG. For all dentin surfaces, except for that prepared with SiC, SE2 demonstrated better etching efficacy on different smear layers, whereas SBU provided only superficial interaction.
本研究使用透射电子显微镜（TEM），调查了采用不同方法制备牙本质表面后玷污层的特征。此外，本研究还使用扫描电子显微镜（SEM）分析了玷污层与随后用于处理牙本质表面的各种酸性试剂之间的相互作用。根据以下五种器械操作方法之一制备牙冠中部牙本质表面：折断；用硬质合金车针研磨；用常规粒度金刚石车针研磨；用超细粒度金刚石车针研磨；或用600目碳化硅（SiC）砂纸研磨。然后，将每个制备好的牙本质表面进一步分为对照组（不进行进一步处理）或用以下试剂之一进行处理：磷酸溶液（PAS）；磷酸凝胶（PAG）；Clearfil SE Bond 2底漆（SE2）；或Scotchbond通用粘合剂（SBU）。制作纵向超薄切片用于TEM观察。制作代表上述每种表面制备和处理方法的牙本质圆盘，并通过SEM检查其形态。TEM结果显示，根据用于制备牙本质表面的不同器械操作方法，玷污层的厚度和密度存在差异。两种形式的磷酸在所有组中均完全去除了玷污层。用PAG蚀刻后，在胶原层顶部观察到聚集的二氧化硅颗粒。对于所有牙本质表面，除了用SiC制备的表面外，SE2在不同玷污层上表现出更好的蚀刻效果，而SBU仅提供表面相互作用。
