title: Pathogen of root surface caries in the elderly.
abstract: OBJECTIVE
  To study the pathogen of root surface caries in the elderly.
  
  
  METHODS
  Plaque samples from the experimental group and the control group were collected. After culturing in selective and non-selective media, the different bacteria were isolated. The counts and the positive rates of total bacteria, porphyromonas group, pervotella group, streptococcus mutants group, actinomyces group and lactobacillus group were compared.
  
  
  RESULTS
  The counts of total bacteria, streptococcus mutants, actinomyces and lactobacillus of the experimental group were higher than those of the control group. The positive rates of actinomyces and lactobacillus of the experimental group were significantly higher than those of the control group.
  
  
  CONCLUSIONS
  Actinomyces and lactobacillus are the main related pathogens of root surface caries in the elderly.
authors.affiliation: Department of Stomatology, Beijing Hospital, Beijing 100730, China.
authors.forename: T
authors.initials: T
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Yang
mesh_terms: D000190:Actinomyces / Q000302:isolation & purification; D000368:Aged; D001419:Bacteria / Q000302:isolation & purification*; D003731:Dental Caries / Q000382:microbiology*; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification; D008875:Middle Aged; D013295:Streptococcus mutans / Q000302:isolation & purification