Many studies have reported about the toxicity of plaque and the importance of brushing for plaque control. However, patients should pause in their brushing for 7 to 10 days after oral surgery, e.g; few studies reported about plaque-induced influence in 7 to 10 days on periodontal tissue. The purpose of this study was to clarify this influence. We selected 6 volunteers as subjects. They were without periodontal disease or systemic disease, and they had taken no medication within 1 month. No. 3 or No. 14 was selected as the subjective tooth, and the other was used as control. The subjects stopped brushing on the subjective tooth side for 1 week. We measured the following parameters : pH and bacteria flora in gingival crevicular fluid, pocket depth, and bleeding associated with probing. These measurements were done on the 1st, 3rd, 5th, and 7th days. After 7th day's measurement, subjects restarted brushing, and we measured pH, pocket depth, and bleeding 2 days later. The results were follows : pocket depth and bleeding showed no changes in all subjects. One subject showed pH and bacteria flora changing on the 7th day. The aerobes ratio in the bacteria flora was lower than anaerobes on the 1st day and became higher on the 7th day. Although another subject showed the same bacteria flora change, the pH did not change. The other subjects showed no change in either pH or bacteria flora. These results suggested that if patients have healthy oral conditions, the stopping brushing for about 1 week evoked little change in periodontal tissue.
The culture-filtrate and the cell-debris fractions of a human oral flagellated protozoa, Trichomonas tenax, were examined for the degradation of sheep and human hemoglobin. The cell-debris fraction had activity to degrade hemoglobin, which was inhibited by a cysteine protease inhibitor, E-64. The degradation seemed to be due to the digestion of globin polypeptides.