title: Endodontic therapy associated with calcium hydroxide as an intracanal dressing: microbiologic evaluation by the checkerboard DNA-DNA hybridization technique.
abstract: This study evaluated the predominant microbiota of infected necrotic pulps and the effects of calcium hydroxide therapy on these microorganisms by the checkerboard DNA-DNA hybridization technique. Conventional endodontic therapy associated with calcium hydroxide as intracanal dressing was performed in 12 single-rooted teeth with pulp necrosis and periradicular bone lesion. Samples were collected from the canal at baseline and 14 days after therapy, and the presence of 44 bacterial species was determined by the checkerboard method. Significant differences in the microbiota from baseline to post-therapy were sought by the paired-samples t test. The most prevalent species included F. nucleatum ss. vincentii, C. sputigena, C. ochracea, S. constellatus, V. parvula, P. gingivalis, P. melaninogenica, and S. sanguis. Most of the microorganisms were reduced after treatment, particularly A. gerencseriae, A. israelii, A. naeslundii, C. gingivalis, C. ochracea, P. gingivalis, S. noxia, S. sanguis, and S. oralis (p < 0.05). Conversely, A. actinomycetemcomitans, C. sputigena, and E. corrodens increased in numbers after therapy. These results indicate that conventional endodontic therapy with calcium hydroxide results in the reduction of pathogenic species associated with pulp necrosis. However, its use is limited, because it did not eliminate the whole spectrum of microorganisms.
authors.affiliation: Institute of Microbiology, Federal University of Rio de Janeiro, Brazil. soso@osite.com.br
authors.forename: Carlos Alberto Soriano
authors.initials: CA
authors.lastname: de Souza
authors.forename: Ricardo Palmier
authors.initials: RP
authors.lastname: Teles
authors.forename: Renata
authors.initials: R
authors.lastname: Souto
authors.forename: Mario Augusto Escobar
authors.initials: MA
authors.lastname: Chaves
authors.forename: Ana Paula Vieira
authors.initials: AP
authors.lastname: Colombo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D002126:Calcium Hydroxide / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000032:analysis; D003790:Dental Pulp Necrosis / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009693:Nucleic Acid Hybridization / Q000379:methods; D010485:Periapical Periodontitis / Q000382:microbiology; D012388:Root Canal Irrigants / Q000494:pharmacology*
chemical_list: D004269:DNA, Bacterial; D012388:Root Canal Irrigants; D002126:Calcium Hydroxide