EFFECT OF UREA CONCENTRATION ON HUMAN PLAQUE PH LEVELS IN SITU
EFFECT OF UREA CONCENTRATION ON HUMAN PLAQUE PH LEVELS IN SITU
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DOI：
10.1016/0003-9969(67)90183-5
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发表时间：
1967-01-01
影响因子：
3
通讯作者：
KLEINBERG, I
中科院分区：
文献类型：
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作者：
KLEINBERG, I
将浓度在0~16.7%(w/v)的尿素溶液作用于牙菌斑不同时间，测量菌斑pH值的变化长达2小时。用SB法测定pH值。研究对象为3天未刷牙且至少12小时未进食的受试者的微电极。将尿素溶液短期应用于斑块，导致初始pH迅速上升，然后缓慢下降。当尿素溶液被施入较长时间时，pH升高，如果加入足够长的时间，pH达到一渐近线，其水平是尿素浓度的函数。一旦达到渐近线，不能在斑块上进一步施加尿素溶液，会导致pH值立即下降到基线。短时间使用高浓度尿素溶液可得到与长时间使用低浓度尿素溶液所观察到的pH曲线相似的结果。数据显示，尿素水平与唾液中的尿素水平相当，可以引起菌斑pH的升高，相当于以前在禁食受试者中报道的菌斑和唾液之间的pH差。
Urea solutions, varying in concentration between 0 and 16.7% (w/v) were applied to dental plaques in situ for different lengths of time and the resulting changes in plaque pH were measured for periods up to 2 hrs. The pH was measured with Sb. micro-electrodes in subjects who had not brushed their teeth for 3 days and had not eaten for at least 12 hr. Application of urea solutions to the plaques for short periods of time resulted in an initial rapid rise in pH followed by a slow pH fall. When the urea solutions were applied for longer time periods, the pH rose higher than previously and, if added for a sufficiently long time, the pH reached an asymptote, the level of which was a function of the urea concentration. Once an asymptote was reached, failure to apply further urea solution to the plaque resulted in an immediate fall in the pH towards the base-line. Applications of solutions of high urea concentration for short periods of time resulted in pH curves similar to those observed when solutions of low urea concentration were applied for longer time periods. The data showed.that urea levelaequMialent to those in saliva could produce a rise in plaque pH equivalent to the difference in pH be -tween plaque and saliva which has been reported previously in fasting subjects.