title: Study on the relationship between Helicobacter pylori in the dental plaque and the occurrence of dental caries or oral hygiene index.
abstract: BACKGROUND
  The aims of our study were to determine the presence of Helicobacter pylori DNA in the dental plaque of Chinese children aged 3-6 years by nested polymerase chain reaction (PCR) and to investigate the relationship between this infection and the occurrence of dental caries or oral hygiene index.
  
  
  METHODS
  Two hundred and fourteen children from a kindergarten in Guangzhou City of China were evaluated. The children's plaques were assessed by plaque indices of Quigley-Hein. Dental plaque was analyzed using nested PCR for two sets of primers directed to the 860-bp fragment of H. pylori genomic DNA, which have been reported to be highly sensitive and specific by other researchers.
  
  
  RESULTS
  H. pylori was detected in dental plaque samples from 126 children, and 70 children with dental caries carried H. pylori in dental plaque. Of these children without infection, only 36 of 88 suffered dental caries. Besides, the average dental plaque index of 126 H. pylori-positive children was higher than that of 88 children without infection. In the present study, there was a significant correlation between H. pylori infection and dental caries or dental hygiene.
  
  
  CONCLUSIONS
  The oral cavity may be a reservoir for H. pylori infection in children. H. pylori in dental plaque may play a role in the occurrence of dental caries, and poor oral hygiene may represent a risk factor for H. pylori in the oral cavity.
authors.affiliation: Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Huanjian
authors.initials: H
authors.lastname: Lin
authors.forename: Yang
authors.initials: Y
authors.lastname: Bai
authors.forename: Xiaoshu
authors.initials: X
authors.lastname: Qin
authors.forename: Xin
authors.initials: X
authors.lastname: Zheng
authors.forename: Yong
authors.initials: Y
authors.lastname: Sun
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D003731:Dental Caries / Q000453:epidemiology / Q000382:microbiology*; D003773:Dental Plaque / Q000453:epidemiology / Q000382:microbiology*; D004197:Disease Reservoirs / Q000382:microbiology; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D009911:Oral Hygiene Index; D016133:Polymerase Chain Reaction