The aim of this study was to establish of caries prevention, and to examine the relationship between dental caries and surroundings factors, based on life habits and caries activity during the deciduous dentition period. Furthermore, since glucosyltransferase, which is a synthetic enzyme of water insoluble glucan in mutans streptococci, is strongly involved in the occurrence of caries, the relationship between deciduous tooth caries and the expression of gtfB in Streptococcus mutans or gtfl in Streptococcus sobrinus was also investigated.
In this study, I research on 114 children in Nagano, and performed a caries activity test (Mucount®) and investigated environmental factors, by asking parents to fill out questionnaires. I also collected dental plaque from brushing from 36 children.
χ²analysis of the relationship between dental caries and environmental factors was performed. The expression of gff was also examined using Real-time PCR, and comparison evaluation was carried out by classifying the children into three groups based on the severity of their dental caries.
Among the results of the Real-time PCR analysis, the incidence of gtfB expression was 14.3% in the non-caries group,41.7% in the low caries group, and 100.0% in the high caries group, there was considerable gtfB expression in the high caries group. The incidence of gtfl expression was 8.3% in the low caries group, and 30.0% in the high caries group. More gtfB expression was consequently, noted in the caries group, and the gtfl expression was lower than the gtfB expression.
Furthermore, there is a tendency that for children who showed gtfB expression, the living environment was irregular, and the level of knowledge of the parents concerning caries was low.
These results suggested the occurrence of caries in deciduous tooth is related not only to the number of Streptococcus mutans and Streptococcus sobrinus, but also to pathogenic factors such as the gtfB and gffl expressions; Caries activity became higher under these conditions. It was also suggested that improvement in living environment is an important approach to prevent caries in deciduous tooth and to decrease the occurrence of serious caries.
It is considered that understanding of living environment, of the children and the bacterial risk during growth is useful for motivating their parents as an index of instruction in caries prevention.