AN ANALYSIS OF FACTORS INFLUENCING DIFFUSION FROM DENTAL PLAQUE INTO A MOVING FILM OF SALIVA AND THE IMPLICATIONS FOR CARIES
AN ANALYSIS OF FACTORS INFLUENCING DIFFUSION FROM DENTAL PLAQUE INTO A MOVING FILM OF SALIVA AND THE IMPLICATIONS FOR CARIES
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DOI：
10.1177/00220345890680110301
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发表时间：
1989-11-01
影响因子：
7.6
通讯作者：
DAWES, C
中科院分区：
文献类型：
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作者：
DAWES, C
最近的研究表明，口腔中的唾液以仅约0.1mm厚的膜存在，并且该膜在口腔的不同区域中以不同的速率（约0.8至7.6mm/min）移动。KCl，作为一种模型扩散剂，从琼脂糖凝胶在口腔中的不同部位的清除率也被发现有显着差异，并已提出，这些变化与唾液膜的速度差异。已经开发了一个计算机模型，用于预测从可变尺寸的斑块扩散到0.1 mm厚的流体膜中的物质的清除半衰期，以不同的速度移动。结果表明，在计算的速度范围内发生在口腔中，清除半衰期是直接相关的流体通过的斑块的长度，并呈负相关的唾液膜速度。该模型的预测与物理模型的实验结果吻合良好。测试了唾液膜速度对pH曲线形状的预测效果，pH曲线的形状由牙菌斑暴露于饱和蔗糖溶液开始，然后是正常的唾液清除。低唾液膜速度，pH值下降更大，更长。这些结果与龋齿的位点特异性有关，因为它们意味着，给定两个面积、深度和微生物组成相同的牙菌斑样本，位于唾液膜速度较低的口腔区域的样本在暴露于可发酵碳水化合物后将显示出更广泛和更长的pH值下降。
Recent studies have indicated that saliva in the mouth is present as a film only about 0.1 mm thick, and that this film moves at different rates (about 0.8 to 7.6 mm/min) in different regions of the oral cavity. The clearance rates of KCl, as a model diffusant, from agarose gels at different sites in the mouth have also been found to vary markedly, and it has been proposed that these variations are related to differences in the velocity of the salivary film. A computer model has been developed for prediction of clearance half-times for substances diffusing from plaque of variable dimensions into a film of fluid 0.1 mm thick, moving at different velocities. The results show that over the range of velocities calculated to occur in the mouth, the clearance half-times are directly related to the length of plaque over which the fluid passes, and inversely related to the salivary film velocity. The predictions of the model are in good agreement with experimental results from a physical model. Tests were made of the predicted effect of salivary film velocity on the shape of the pH curve initiated by exposure of plaque to a saturated sucrose solution, followed by normal salivary clearance. With a low salivary film velocity, the fall in pH was greater and more prolonged. These results are relevant to the site-specificity of caries, since they imply that, given two plaque samples of identical area, depth, and microbial composition, the sample located in a region of the mouth where the salivary film velocity is lower will show a more extensive and prolonged pH fall after exposure to fermentable carbohydrate.