title: Advanced Caries Microbiota in Teeth with Irreversible Pulpitis.
abstract: BACKGROUND
  Bacterial taxa in the forefront of caries biofilms are candidate pathogens for irreversible pulpitis and are possibly the first ones to invade the pulp and initiate endodontic infection. This study examined the microbiota of the most advanced layers of dentinal caries in teeth with irreversible pulpitis.
  
  
  METHODS
  DNA extracted from samples taken from deep dentinal caries associated with pulp exposures was analyzed for the presence and relative levels of 33 oral bacterial taxa by using reverse-capture checkerboard hybridization assay. Quantification of total bacteria, streptococci, and lactobacilli was also performed by using real-time quantitative polymerase chain reaction. Associations between the target bacterial taxa and clinical signs/symptoms were also evaluated.
  
  
  RESULTS
  The most frequently detected taxa in the checkerboard assay were Atopobium genomospecies C1 (53%), Pseudoramibacter alactolyticus (37%), Streptococcus species (33%), Streptococcus mutans (33%), Parvimonas micra (13%), Fusobacterium nucleatum (13%), and Veillonella species (13%). Streptococcus species, Dialister invisus, and P. micra were significantly associated with throbbing pain, S. mutans with pain to percussion, and Lactobacillus with continuous pain (P < .05). Quantitative polymerase chain reaction revealed a mean total bacterial load of 1 × 10(8) (range, 2.05 × 10(5) to 4.5 × 10(8)) cell equivalents per milligram (wet weight) of dentin. Streptococci and lactobacilli were very prevalent but comprised only 0.09% and 2% of the whole bacterial population, respectively.
  
  
  CONCLUSIONS
  Several bacterial taxa were found in advanced caries lesions in teeth with exposed pulps, and some of them were significantly associated with symptoms. A role for these taxa in the etiology of irreversible pulpitis is suspected.
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Isabela N
authors.initials: IN
authors.lastname: Rôças
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Kenio C
authors.initials: KC
authors.lastname: Lima
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Isauremi V
authors.initials: IV
authors.lastname: Assunção
authors.affiliation: Department of Preventive Dentistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Patrícia N
authors.initials: PN
authors.lastname: Gomes
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Igor V
authors.initials: IV
authors.lastname: Bracks
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: jose.siqueira@estacio.br.
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira
mesh_terms: D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000145:classification*; D002648:Child; D003731:Dental Caries / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota; D011671:Pulpitis / Q000382:microbiology*; D055815:Young Adult
keywords: Dentinal caries; Lactobacillus; Streptococcus; irreversible pulpitis; microbiota; molecular biology; permanent teeth