title: Longitudinal study of dental caries incidence associated with Streptococcus mutans and Streptococcus sobrinus in pre-school children.
abstract: Streptococcus mutans and Streptococcus sobrinus are known to be associated with the development of dental caries. In this study these bacteria were detected in pre-school children (each with primary dentition, age range 3-5 years, n = 60) using a PCR method, and then their presence was compared with the incidence of dental caries over a 1-year period. Plaque samples were collected from all erupted tooth sites using a sterile toothbrush. Dental examinations at the beginning of the study (baseline) and after 1 year were also performed to determine decayed, missing, filled teeth (dmft) scores using WHO caries diagnostic criteria. The prevalences of S. mutans and S. sobrinus across all the subjects were 61.7% and 56.6%, respectively; 13 subjects (21.7%) were positive for S. mutans alone, 10 (16.6%) were positive for S. sobrinus alone and 24 (40.0%) were positive for both S. mutans and S. sobrinus, whereas 13 (21.7%) were negative for both S. mutans and S. sobrinus. dmft scores of subjects positive for both S. mutans and S. sobrinus at baseline and after 1 year were significantly higher than of those positive for S. mutans alone at the same stages (P < 0.01 and P < 0.001, respectively). The caries incremental increase was also significantly greater in those with both bacteria detected (P < 0.05). Our results indicate that pre-school children harbouring both S. mutans and S. sobrinus have a significantly higher incidence of dental caries than those with S. mutans alone.
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Mitsugi
authors.initials: M
authors.lastname: Okada
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Soda
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Hayashi
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Doi
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Suzuki
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Miura
authors.affiliation: Department of Pediatric Dentistry, Hiroshima University Faculty of Dentistry, Hiroshima, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Kozai
mesh_terms: D002675:Child, Preschool; D003731:Dental Caries / Q000453:epidemiology* / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013295:Streptococcus mutans / Q000302:isolation & purification*; D016986:Streptococcus sobrinus / Q000302:isolation & purification*