title: Prevalence of black-pigmented bacteroides species in root canal infections.
abstract: The prevalence of black-pigmented Bacteroides species in the root canals of 72 teeth with apical periodontitis was evaluated. Twenty-two of the canals contained one or more species of black-pigmented Bacteroides. Bacteroides intermedius (14 strains) and Bacteroides endodontalis (5 strains) were most common. Of the species Bacteroides gingivalis, Bacteroides loeschei, and Bacteroides denticola, 2, 3, and 1 strains, respectively, were isolated. The median number of bacterial cells recovered from the root canals containing black-pigmented Bacteroides was 2.8 x 10(5) and from the other canals 3.0 x 10(3). The mean number of strains was 7.9 and 3.3, respectively. Sixteen of the 22 root canals containing black-pigmented Bacteroides species were associated with acute apical abscesses and purulent drainage through the root canal. The other six teeth with black-pigmented Bacteroides were asymptomatic. One additional abscess was present among the 72 cases. This root canal contained Actinomyces israelii and Actinomyces naeslundii.
authors.forename: G
authors.initials: G
authors.lastname: Sundqvist
authors.forename: E
authors.initials: E
authors.lastname: Johansson
authors.forename: U
authors.initials: U
authors.lastname: Sjögren
mesh_terms: D000190:Actinomyces / Q000302:isolation & purification; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001439:Bacteroides / Q000302:isolation & purification*; D003788:Dental Pulp Diseases / Q000382:microbiology*; D006801:Humans; D008875:Middle Aged