title: Microbiota of dentinal caries as assessed by reverse-capture checkerboard analysis.
abstract: OBJECTIVE
  This study aimed to identify the microbiota of different layers of dentinal caries by using a culture-independent molecular biology approach.
  
  
  METHODS
  DNA was extracted from samples taken from 3 distinct layers (superficial, middle and deep) of advanced occlusal caries and analyzed for the presence and relative levels of 28 oral bacterial species/phylotypes using a reverse-capture checkerboard hybridization assay.
  
  
  RESULTS
  The mean number of target taxa per layer was 7.7 (± 3.96) in the superficial, 7 (± 3.4) in the middle, and 6.3 (± 3.04) in the deep layer. No statistical significance was observed for these differences (p = 0.36). Overall, the most prevalent taxa in the 3 layers were Atopobium genomospecies C1 (72.5%), Fusobacterium nucleatum (69%), Lactobacillus casei (68%), Veillonella species (55%) and Lactobacillus fermentum (52%). No differences were found in the prevalence rates of the most frequent target species in the 3 layers. The most prevalent taxa found at levels above 10(5) in the advanced front line of deep-dentin caries were Atopobium genomospecies C1, F. nucleatum, Streptococcus mutans, Streptococcus species and Veillonella species.
  
  
  CONCLUSIONS
  The present results revealed that the prevalences of several established or candidate caries pathogens do not differ significantly in the different zones of dentinal caries lesions. The finding that some as-yet-uncharacterized species and novel species were found in high frequencies join other molecular studies to include them in the set of candidate caries pathogens.
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, Brazil.
authors.forename: K C
authors.initials: KC
authors.lastname: Lima
authors.forename: L T
authors.initials: LT
authors.lastname: Coelho
authors.forename: I V A
authors.initials: IV
authors.lastname: Pinheiro
authors.forename: I N
authors.initials: IN
authors.lastname: Rôças
authors.forename: J F
authors.initials: JF
authors.lastname: Siqueira
mesh_terms: D039903:Actinobacteria / Q000302:isolation & purification; D000293:Adolescent; D015373:Bacterial Typing Techniques; D016009:Chi-Square Distribution; D002648:Child; D004269:DNA, Bacterial / Q000032:analysis*; D003731:Dental Caries / Q000382:microbiology*; D003804:Dentin / Q000382:microbiology* / Q000473:pathology; D005260:Female; D005673:Fusobacterium / Q000302:isolation & purification; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification; D008297:Male; D008963:Molar; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D018709:Statistics, Nonparametric; D014678:Veillonella / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial