Correlation between the Amount of Glucosyltransferase-B and the Decayed, Missing and Filled Teeth Index in Oral Samples

抄録

Glucosyltransferase B (GTF-B) secreted from Streptococcus mutans (S. mutans) is considered to be the most important virulence factor of cariogenic biofilm formation for its high enzymatic activity in the synthesis of water-insoluble glucans. The quantity of GTF-B protein in the saliva or plaque is readily measurable for the estimation of caries risk in an individual. However, previous reports have indicated that GTF-B-secreting ability varies among S. mutans strains harbored by subjects. In this study, we examined the correlation among the quantity of GTF-B protein, the quantity of S. mutans, and the decayed, missing and filled teeth (DMFT) index in oral samples. Our results showed a clear positive correlation between GTF-B quantity and S. mutans quantity in oral samples. Furthermore, a brushing-plaque sample was more useful than a stimulated saliva sample for the estimation of caries risk. In addition, in the brushing-plaque samples, the caries-susceptible group was infected with S. mutans strains that had a higher ability to secrete GTF-B enzyme than those of the caries-free and low-level caries groups. These results suggested that GTF-B-producing ability differed among individuals and the risk of caries predicted from the amount of GTF-B seemed to be proportional to the DMFT index. Taken together, the quantity of GTF-B protein is useful for the estimation of caries risk.