title: One-session root canal treatment with antimicrobial photodynamic therapy (aPDT): an in vivo study.
abstract: OBJECTIVE
  To evaluate the response of the apical and periapical tissues of dog teeth with apical periodontitis after one-session root canal treatment with and without antimicrobial photodynamic therapy (aPDT) compared with the use of an intracanal dressing.
  
  
  METHODS
  Sixty root canals with an induced periapical lesion were instrumented and assigned to three groups: I, two-session root canal treatment using antibacterial dressing with calcium hydroxide-based paste; II, one-session root canal treatment using aPDT; and III, one-session root canal treatment in which the root canals were filled immediately after biomechanical preparation. The animals were euthanized after a 90-day experimental period. The maxillas and mandibles with teeth were submitted to histotechnical processing and haematoxylin-eosin staining. Descriptive microscopic analysis of the apical and periapical region characteristics was performed, as well as morphometric assessment of the periapical lesion areas in fluorescence microscopy. Quantitative data were analysed statistically by the nonparametric Kruskal-Wallis test and Dunn's post-test (α = 0.05).
  
  
  RESULTS
  Group I was characterized by progressive repair, with the presence of fibres, cells and blood vessels. Group II had periodontal ligaments with the presence of collagen fibres and residual inflammatory cells. Group III had a dense inflammatory infiltrate with extensive oedematous areas and fibrillar dissociation, suggesting a persistent inflammatory and resorptive condition. Regarding periapical lesion size, group I had significantly smaller lesions (P < 0.05) than groups II and III, which did not differ significantly from each other.
  
  
  CONCLUSIONS
  Two-session root canal treatment using a calcium hydroxide-based dressing was associated with significantly smaller periapical lesions at 90 days and characterized by progressive repair.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: M C
authors.initials: MC
authors.lastname: Borsatto
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Correa-Afonso
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: M P
authors.initials: MP
authors.lastname: Lucisano
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: R A
authors.initials: RA
authors.lastname: Bezerra da Silva
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: F W G
authors.initials: FW
authors.lastname: Paula-Silva
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: P
authors.initials: P
authors.lastname: Nelson-Filho
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: L A
authors.initials: LA
authors.lastname: Bezerra da Silva
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D004285:Dogs; D008856:Microscopy, Fluorescence; D010485:Periapical Periodontitis / Q000188:drug therapy* / Q000628:therapy; D010778:Photochemotherapy / Q000379:methods*; D012390:Root Canal Therapy / Q000379:methods*
chemical_list: D000890:Anti-Infective Agents
keywords: antibacterial dressing; antimicrobial photodynamic therapy; apical periodontitis; calcium hydroxide; one-session endodontic treatment; two-session endodontic treatment