3M ESPE Dental Products, Saint Paul, MN, USA.
J Dent. 2010 Mar;38(3):245-52. doi: 10.1016/j.jdent.2009.11.004. Epub 2009 Nov 27.
Resin-modified glass ionomers (RMGI) have demonstrated clinical success in their ability to minimize post-operative sensitivity of restorations. RMGIs have been recently introduced as paste-liquid systems for convenience of clinical usage. The objective of this study was to measure the ability of a new paste-liquid RMGI liner/base to reduce fluid flow through human dentin.
Dentin permeability was measured on human crown sections on etched dentin, using etched dentin as a model for the exposed tubules typical of root sensitivity, and permitting measurement of the maximum permeability. In the one group, the etched dentin was coated with the RMGI, and pre- and post-treatment permeability was measured on the coated dentin. In the second group, a smear layer was created on the dentin with sandpaper, then the samples were coated with the RMGI; permeability was measured on the smeared and coated dentin. Samples from each group were sectioned and examined via scanning electron microscopy (SEM).
The new paste-liquid RMGI liner/base significantly reduced fluid flow through dentin, and exhibited excellent seal on dentin with either a smear layer or open tubules. SEM images show evidence that the RMGI infiltrated the smear layer with resin during placement, penetrated dentin tubules, and formed resin tags in acid-etched dentin.
Based on these results, combined with previous research on adhesion and microleakage, it is concluded that the new RMGI liner/base should minimize post-operative sensitivity in restorations.
树脂改性玻璃离子体（RMGI）在减少修复后敏感方面的临床效果显著。为了方便临床使用，最近推出了 RMGI 糊剂-液体系统。本研究的目的是测量新型糊剂-液体 RMGI 衬垫/基底减少人牙本质液流的能力。
用人牙冠片的牙本质进行牙本质通透性测量，用酸蚀牙本质模拟暴露的小管，以代表根敏感的典型暴露小管，并允许测量最大通透性。在一组中，将 RMGI 涂覆在酸蚀牙本质上，然后在涂覆牙本质上测量预处理和后处理的通透性。在第二组中，用砂纸在牙本质上形成玷污层，然后用 RMGI 涂覆样本；测量玷污和涂覆牙本质的通透性。从每组样本中切取并通过扫描电子显微镜（SEM）进行检查。
新型糊剂-液体 RMGI 衬垫/基底显著减少了牙本质的液流，并且在有玷污层或开放小管的牙本质上表现出良好的密封。SEM 图像显示，RMGI 在放置过程中用树脂渗透玷污层，渗透牙本质小管，并在酸蚀牙本质中形成树脂标记。
基于这些结果，结合之前关于黏附性和微渗漏的研究，可以得出结论，新型 RMGI 衬垫/基底应能最大限度地减少修复后的敏感问题。
