Examination of the histological and bacteriological features of the interface between bacterial deposits and root dentin using a device that included exposed root dentin reproduced pulpal pressure in vitro.

使用包含暴露的牙根牙本质的装置检查细菌沉积物和牙根牙本质之间的界面的组织学和细菌学特征，并在体外再现牙髓压力。

基本信息

批准号：
11671896
负责人：
OZAKI Kazumi
金额：
$ 2.24万
依托单位：
The University of Tokushima, School of Dentistry
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11671896/
关键词：
Caries-associated bacteria Pulpal pressure Intracellular polysaccharide 菌体関連多糖

项目摘要

We evaluated structural change of the dentin and alteration of the localization and carbohydrate metabolism of bacteria in dental plaque and into dentinal tubules on the root dentin specimens in vitro and in situ, that we could observe with the progress in the time. In vitro experiments demonstrated that pH of the medium used for mixed culture with Streptococcus mutans and Lactobacillus casei was lower than it of the independent culture on a device which reproduced pulpal pressure by supplying the saline pressurized through dentinal tubules exposed in the pulpal side of root dentin specimens.On microscope analysis, the numbers of bacterially infected dentinal tubules in specimens used for the mixed culture was significantly more abounding than it of the independent culture. By periodate-thiocarbohydrazide-silver proteinate-physical development (PTSP) staining method, which could detect the intracellular polysaccharide in bacterial cells, it was clarified that much intracellular polysaccharide exists in most bacteria within which exist in microcolonies of plaque layer nearest the dentin surface and in which invaded into dentinal-tubules.On the other hand, in a root-dentin specimen, compulsorily exposed the surface and to the oral environment for only two months, the penetration of the bacteria into the dentinal tubules was visible, while in a twelve-month root-surface specimens in situ, some microcavities coalesced an indicated more wide-ranging cavities, but subsequent destruction of the dentin was not observed. The existence of mantle dentine was indicated as the factor by which brought about the difference of these results. It became clear to dynamically change in the time-dependent destruction of the dentin, which progresses on localization and abundance ratio of PTSP-positive-bacteria by means of image processing technology by the computer.

我们在体外和原位评估了根牙本质标本上牙本质的结构变化以及牙菌斑和牙本质小管中细菌的定位和碳水化合物代谢的变化，我们可以随着时间的推移观察到这些变化。体外实验表明，用于变形链球菌和干酪乳杆菌混合培养的培养基的pH值低于在通过暴露于牙根牙本质牙髓侧的牙本质小管提供加压盐水来再现牙髓压力的装置上独立培养的培养基的pH值。显微镜分析发现，混合培养标本中细菌感染的牙本质小管数量明显多于独立培养标本。采用可检测细菌细胞内多糖的高碘酸盐-硫代碳酰肼-银蛋白盐-物理显影（PTSP）染色法，阐明大多数细菌中存在大量的细胞内多糖，其存在于最接近牙本质表面的牙菌斑层的微菌落中，另一方面，在牙根牙本质标本中，强制暴露表面和口腔环境仅两个月，渗透细菌进入牙本质小管的过程是可见的，而在十二个月的原位根表面标本中，一些微腔合并并表明有更广泛的腔，但没有观察到随后的牙本质破坏。表明地幔牙本质的存在是造成这些结果差异的因素。通过计算机图像处理技术，牙本质的破坏随着时间的推移而动态变化，PTSP阳性细菌的定位和丰度比不断变化，这一点变得很清楚。