title: Five-year longitudinal study of dental caries risk associated with Streptococcus mutans and Streptococcus sobrinus in individuals with intellectual disabilities.
abstract: Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) are important etiologic agents in human dental caries. Using quantitative real-time polymerase chain reaction assays for the presence of those strains, we examined 145 outpatients with intellectual disability (ID), calculated the proportion of each of these strains to total bacteria, and compared dental caries incidence over 5 years. Plaque samples were collected from all erupted tooth sites, and dental examinations were performed annually to determine numbers of decayed, missing, and filled teeth (DMFT score; World Health Organization caries diagnostic criteria). Elevated DMFT scores were calculated as ∆DMFT, and sites of newly affected caries (∆SNAC) were identified. Sixty-six patients had both strains. The proportion of S. mutans to total bacteria was moderately correlated with DMFT in year 2, ∆DMFT in years 2 and 5, and ∆SNAC in years 2 and 5 (correlation coefficient = 0.470, P < 0.001), while the proportion of S. sobrinus to total bacteria was moderately correlated with DMFT in years 2 and 5, ∆DMFT in years 1, 2, and 5, and ∆SNAC in years 2 and 5 (correlation coefficient = 0.695, P < 0.001). Individuals with ID who harbored both bacterial strains had a higher risk of dental caries and a significantly higher proportion of S. sobrinus to total bacteria.
authors.affiliation: Department of Special Care Dentistry, Hiroshima University Hospital.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Oda
authors.forename: Fumiko
authors.initials: F
authors.lastname: Hayashi
authors.forename: Atsuko
authors.initials: A
authors.lastname: Wakita
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Nagatani
authors.forename: Mitsugi
authors.initials: M
authors.lastname: Okada
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003731:Dental Caries / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000150:complications*; D008137:Longitudinal Studies; D008297:Male; D013295:Streptococcus mutans / Q000472:pathogenicity*; D016986:Streptococcus sobrinus / Q000472:pathogenicity*; D055815:Young Adult