The establishment of caries risk diagnosis by the pH monitoring.

本会计年度研究了以下内容：同时监测口腔内3个位置的pH值，通过唾液流速的变化，考察唾液对pH值变化的影响。检测唾液流速、pH值、个人缓冲能力的变化，并监测斑块沉积后，糖溶液降低pH值后的恢复情况。校正后，所有考生的LALi的pH值与校正液的pH值（pH值为6.86）相比几乎没有变化，直到被酸性溶液冲洗，而UPB和UAB区域的pH值降至6.2左右。用酸性饮料漱口后，pH值降至3.3，并逐渐恢复。在LALi区，pH值恢复到初始pH值的平均时间为92.2±89.1秒，而在UPB和UAB区，pH值恢复到初始pH值的速度非常慢，在冲洗后30分钟，UPB和UAB的平均pH值分别为5.1±0.3和4.7±0.3。两者与LALi位点的pH值有显著差异（p<0.001）。唾液流速、pH值和缓冲容量的个体范围相对于整体范围变化很大。受刺激唾液中钙、磷酸盐浓度的变化小于未受刺激唾液中钙、磷酸盐浓度的变化，成人唾液流量与缓冲容量呈正相关（p<0.05）。在检测糖溶液降低pH值后pH值恢复的实验中，菌斑很难沉积在传感器上，实验方法的改进似乎是必要的。

The following was studied in this fiscal year. The pH of 3 positions in the oral cavity is monitored simultaneously, by the change of the salivary flow rate, and also examined the effect of saliva on the change of pH. Flow velocity, pH, personal change of buffer capacity of the saliva are examined and after the plaque deposits, the aspect of the recovery after pH decrease by sugar solution is monitored.After the calibration, the pH of LALi for all examinees hardly changed from that of the adjustment liquid (pH:6.86) until rinsing by the acid solution, while the pH of the UPB and UAB regions was lowered to around 6.2. After rinsing the mouth with the acid beverage, the pH dropped to 3.3, and it gradually recovered. At the LALi region, the mean time of recovery to the original pH was 92.2 ± 89.1 seconds but the pHs at the UPB and UAB regions recovered to the original pH very slowly and at 30 minutes after rinsing, the mean pHs of UPB and UAB were 5.1 ± 0.3 and 4.7 ± 0.3, respectively. Both were significantly different (p<0.001) from the pH at the LALi sites.The individual range of salivary flow rate, pH and the buffer capacity varied considerably relative to the overall range. The variation of the calcium and phosphate concentration in stimulated saliva was smaller than those in unstimulated saliva There was the positive correlation between salivary flow rate and buffer capacity in total adult samples (p<0.05).In the experiment which examines the recovery of pH after pH decrease by the sugar solution, it was difficult that the plaque is made to deposit on the sensor, and the improvement of the experimental method seemed to be the necessity.