牙菌斑中某些细菌使碳水化合物酵解产酸,导致牙齿硬组织脱矿被认为是龋齿发生的直接原因。因此,测定菌斑内pH值的变化规律,对于研究龋齿的病因、评价食物的产酸能力以及探寻有效的防龋方法是十分有意义的。精确测定溶液pH值需用氢离子敏感性电极和pH计。其基本过程是:氢离子敏感性电极与参比电极同时插入待测溶液中,组成类似化学电池的系统,电极分别接pH计,溶液中H~+浓度以电位差的形式反应在pH计上,然后经过仪器内部的负对数转换,在表 Certain bacteria in plaque make carbohydrates digested and acidified, resulting in the demineralization of dental hard tissue is considered to be the direct cause of dental caries. Therefore, the determination of changes in the pH of the plaque, for the study of the etiology of dental caries, evaluate the acid production capacity of food and explore effective anti-caries method is very meaningful. Accurate determination of solution pH value requires hydrogen ion-sensitive electrode and pH meter. The basic process is: hydrogen ion-sensitive electrode and reference electrode simultaneously inserted into the test solution to form a chemical-battery-like system, the electrodes were connected to the pH meter, the solution H ~ + concentration in the form of potential difference in the pH meter , Then pass the negative logarithm of the instrument inside the table