抄録
Oral examination and lactobacillus counts were conducted on a selected group of one hundred school children, and the results obtained were summarized as follows. 1. In 58.3 to 60.2 percents of subjects with carious teeth there were found far higher lactobacillus counts than in subjects with healthy teeth. The mean lactobacillus count in the mouth of the former amounted as much as 3-fold that in the mouth of the latter. 2. There was hardly found any significant correlation between the number of decayed teeth and lactobacillus count. However, the mean lactobacillus counts proved to be generally elevated in subjects having high caries incidence. 3. The mean lactobacillus count in the regular users of tooth-brush proved to be lower than that in non-users.
