Is the Salivary Lactobacillus Count a Valid Index of Activity of Dental Caries?

Abstract

As part of a more general survey of the population of an institution for the feeble-minded, lactobacillus counts from the saliva of 64 teen-aged girls have been compared for 30 mos. with the rates of progress of tooth decay. When massed data were used there was a slight trend toward parallelism of the magnitude of the 2 factors. However, when the group as a whole was subdivided according to the relative rates of caries, there was little difference between the lactobacillus counts of those with the least and those with the greatest progress of tooth decay. Notably high counts were found almost without exception at the time of each examination. Eleven of the girls showed no measureable progress of tooth decay for more than 2.5 yrs. The range of lactobacillus counts for these girls has been contrasted with the range for the entire group, and also with the range for the 15 girls with most rapid progression. The differences between the 3 groups are not great. The inconstancy of relationship between lactobacillus counts and rates of caries progress is such that one cannot consider the test to have been definitive within this group of subjects for the diagnosis or prognosis of caries progress for the individual subject.