Study of caries activity test based on Streptcoccus mutans

relation to the increase of decay after 6 months

Abstract

We have developed a new caries activity test, the “KKY test”, based on Str. mutans in plaque material measured by a colorimetric method.
For the purpose of analyzing the relation between the test score of the caries activity and the increase in caries, 436 kindergarteners were investigated, and their oral status was observed for 6 months.
The average number of increased caries after 6 months was less than 1 in the (-) group, about 1 in the (±) group, and about 1.5 in the (+) group.
A high statistical significance was shown in the relationship between the KKY test and the increase of decay.
Therefore, the KKY test seems useful for measuring caries activity.
It lends itself readily to dental practice, sine observation of color change is much easier than counting the number of bacterial colonies.
It also has the advantage that it can be understood by child patiets.
As a consequence it has value in patient education.