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Atomic force microscopic study of enamel surface changes during development of secondary caries

继发龋发展过程中牙釉质表面变化的原子力显微镜研究

基本信息

批准号：
09470426
负责人：
NAGAMINE Michihiro
金额：
$ 7.36万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09470426/
关键词：
Atomic force microscopy Secondary caries Enamel Demineralization Bacterial adherence Amalgam Composite resin Glass ionomer cement

项目摘要

The purpose of this study is to investigate enamel surface changes adjacent to restorations during development of secondary caries in vitro. We observed demineralized enamel surface (0.6mmX3.6mm) changes adjacent to amalgam (AM), composite resin (CR) and glass ionomer cement (GI) by atomic force microscopy (AFM). The demineralized enamel surfaces were produced by immersing in 0.2M acetic buffer (pH4.0). The amounts of calcium and chemical contents on the enamel surfaces were measured. Moreover, the adherence of Streptococcus mutans MT3940 to the polished or demineralized enamel surfaces adjacent to restorations were detected.The findings were as follows :1. AFM showed depressions at the marginal enamel surface in the specimen restored with CR after demineralization for 2 min., while no change was observed on the enamel adjacent to AM.In both specimens, enamel surfaces were changed morphologically at 5 min. However, no change was detected on the enamel surface adjacent to GI even after 20 min.2. The amounts of calcium demineralized from enamel surfaces adjacent to AM or CR were higher than that of GI.3. The P_20_5 contents on demineralized enamel surfaces at the marginal area of specimen AM and specimen CR were remarkable decrease as compared with the center area on enamel surfaces. While the Ca/P atomic ratio were increased at the marginal area of specimen AM and specimen CR, the Ca/P ratio did not change at any analyzed area of the specimen GI.4. The number of adherence on the enamel surfaces next to GI was less than that of AM and CR.There were no difference of the number of adherence between polished enamel and demineralized enamel.These results indicated that GI inhibited initial demineralization and bacterial adherence on the enamel surface, as compared with AM and CR.AFM was beneficial to these analysis.

本研究的目的是在体外研究继发性龋的发展过程中牙釉质表面与修复体相邻的变化。采用原子力显微镜（AFM）观察脱矿牙釉质表面（0.6mmX3.6mm）在汞合金（AM）、复合树脂（CR）和玻璃离子水门合剂（GI）附近的变化。用0.2M醋酸缓冲液（pH4.0）浸泡脱矿牙釉质表面。测定牙釉质表面的钙含量和化学成分。此外，还检测了变形链球菌MT3940在修复体附近抛光或脱矿的牙釉质表面的粘附性。研究结果如下：1。脱矿2min后，CR修复标本的AFM显示牙釉质边缘表面凹陷，而AM附近牙釉质未见变化。在两个标本中，牙釉质表面在5分钟内发生了形态变化。然而，即使在20分钟后，胃肠道附近的牙釉质表面也没有变化。AM和CR相邻牙釉质表面脱钙量均高于gi。AM和CR脱矿牙釉质表面边缘区域的P_20_5含量明显低于牙釉质表面中心区域。虽然Ca/P原子比在试样AM和CR的边缘区域有所增加，但在试样gi的任何分析区域Ca/P原子比都没有变化。磨光后牙釉质与脱矿后牙釉质的粘附数无显著差异，磨光后牙釉质与脱矿后牙釉质的粘附数无显著差异。这些结果表明，与AM和cr相比，GI抑制了牙釉质表面的初始脱矿和细菌粘附，afm有利于这些分析。