Objectives@#The aim of this study was to investigate the
infection rates of
bacteria associated with
dental caries among
children and
adolescents in
Korea. @*
Methods@#
Oral examinations were conducted in 146
students. The numbers of
bacteria associated with
dental caries, such as
Streptococcus mitis ,
Streptococcus mutans ,
Streptococcus sobrinus , and
Lactobacillus casei , in the subjects’
oral cavity were counted by
real-time PCR, and
infection rates for those
bacteria were additionally investigated. @*Results@#The
infection rate of
Streptococcus mitis ,
Streptococcus mutans ,
Streptococcus sobrinus , and
Lactobacillus casei was 99.3% (145/146), 63.0% (92/146), 1.4% (2/146), and 25.3% (37/146), respectively. The amounts of
Streptococcus sobrinus and
Lactobacillus casei did not differ with the participants’ age. However, the number of
Streptococcus mutans was 537.6 for
primary school students, 5698.2 for middle
school students, and 19037.5 for
high school students. The mean number of oral
bacteria increased with age (P<0.05). The mean bacterial numbers of the infected subjects indicated significant differences in the numbers of
Streptococcus mitis and
Streptococcus mutans (P<0.05). @*Conclusions@#The
infection rates of
Streptococcus mitis and
Streptococcus mutans were distinct in
children and
adolescents. Efforts to control the
bacteria associated with
dental caries are needed to prevent
dental caries.