1983 Volume 33 Issue 1 Pages 6-17
The purpose of this study is to use a newly developed selective medium for Str. mutans in a cries activity test.
The medium contains an indicator dye, bromocresol purple, which changes from purple to yellow in the range of pH 6.8-5.2.
The optimum concentration of growth inhiditors in this medium, phenethyl alcohol and sodium azide, were 0.1% and 0.0075%, resepctively
Mannitol was utilized as a fermentable carbohydrate.
In this medium, the growth Str. mutans serotype a-g groups was not inhibited, butt he multiplication of other oral bacteria was.
When this medium was used to isolate Str. mutans from human plaque, large yellow colonies, rounded and smooth, were observed on the agar plate.
Therefor, we were interested in the application of this medium, which we named “KKY”, in acaries activity test based on the occurrence of Str. mutans in plaque material.
565 children aged from 4 to 6 yaars were tested.
The relation between the KKY test score and present oral status was statistically analyzed. The average number of decayed teeth was about 2 in the (-) group, about 3 in the (±) group, and about 5 in the (+) group, and we recognized a significant difference between each group.
