title: Association of black-pigmented bacteria with endodontic infections.
abstract: Black-pigmented bacteria (BPB) have been associated with endodontic infections. The purpose of this study was to evaluate further the presence of BPB with the clinical signs and symptoms associated with endodontic infections. Microbial samples were collected from the root canals of 40 intact teeth with necrotic pulps and apical periodontitis. Conventional laboratory methods were used for identification of the strains of BPB isolated in pure culture. In addition, the polymerase chain reaction and specific primers for 16S r-RNA genes were used to differentiate Prevotella nigrescens from Prevotella intermedia. Twenty-two (55%) samples were positive for the growth of BPB. Of those, 11 of 22 (50%) were identified as P. nigrescens, 8 of 22 (36%) were P. intermedia, 2 of 22 (9%) were Porphyromonas gingivalis, and 1 of 22 (5%) was Prevotella melaninogenica. Sixteen of the 22 root canals positive for the growth of BPB were associated with purulent drainage either from the root canal or an associated sinus tract. Statistical analysis did not show a significant relationship for the presence of BPB with clinical signs and symptoms.
authors.affiliation: Department of Endodontology, Oregon Health Sciences University School of Dentistry, Portland 97201, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Baumgartner
authors.forename: B J
authors.initials: BJ
authors.lastname: Watkins
authors.forename: K S
authors.initials: KS
authors.lastname: Bae
authors.forename: T
authors.initials: T
authors.lastname: Xia
mesh_terms: D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D003790:Dental Pulp Necrosis / Q000382:microbiology*; D006801:Humans; D010485:Periapical Periodontitis / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000302:isolation & purification / Q000472:pathogenicity; D018720:Prevotella / Q000302:isolation & purification / Q000472:pathogenicity*; D018713:Prevotella intermedia / Q000302:isolation & purification / Q000472:pathogenicity; D001443:Prevotella melaninogenica / Q000302:isolation & purification / Q000472:pathogenicity
chemical_list: D004269:DNA, Bacterial