title: Clinical influence of different intracanal medications on Th1-type and Th2-type cytokine responses in apical periodontitis.
abstract: BACKGROUND
  This clinical study assessed the influence of different intracanal medications on Th1-type and Th2-type cytokine responses in apical periodontitis and monitored the levels of bacteria from primarily infection during endodontic procedures.
  
  
  METHODS
  Thirty primarily infected teeth were randomly divided into 3 groups according to the medication selected: chlorhexidine (CHX), 2% CHX gel; Ca(OH)2/SSL, Ca(OH)2 + SSL; and Ca(OH)2/CHX, Ca(OH)2 + 2% CHX gel (all, n = 10). Bacterial sample was collected from root canals, and the interstitial fluid was sampled from lesions. Culture techniques were used to determine bacterial counts (colony-forming units/mL). Th1 (tumor necrosis factor-α, interferon-γ, and interleukin [IL]-2) and Th2 cytokines (IL-4, IL-5, and IL-13) were measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  All intracanal medication protocols were effective in reducing the bacterial load from root canals (all P < .05) and lowering the levels of Th1-type cytokines in apical lesions (all P < .05), with no differences between them (P > .05). Both Ca(OH)2 treatment protocols significantly increased the levels of Th2-type cytokines (P < .05), with no differences between them (P > .05). Thus, chlorhexidine medication showed the lowest effectiveness in increasing the levels of Th2-type cytokine. After treatment, regardless of the type of medication, the linear regression analysis indicated the down-regulation of Th2-type cytokines by Th1-type cytokines.
  
  
  CONCLUSIONS
  All intracanal medication protocols were effective in reducing bacterial load and lowering the levels of Th1-type cytokines. Thus, the use of Ca(OH)2 medications contributed to the increase in the Th2-type cytokine response in apical periodontitis.
authors.affiliation: Department of Restorative Dentistry, Endodontics Division-UNESP-UNIV Estadual Paulista, São José dos Campos Dental School, São José dos Campos, São Paulo, Brazil; Department of Restorative Dentistry, Endodontics Division, Piracicaba Dental School-State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil. Electronic address: Frederico.martinho@fosjc.unesp.br.
authors.forename: Frederico C
authors.initials: FC
authors.lastname: Martinho
authors.affiliation: Department of Semiology and Clinics, Periodontics Division, Federal University of Pelotas Dental School, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Gustavo G
authors.initials: GG
authors.lastname: Nascimento
authors.affiliation: Department of Semiology and Clinics, Periodontics Division, Federal University of Pelotas Dental School, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Fabio R M
authors.initials: FR
authors.lastname: Leite
authors.affiliation: Department of Restorative Dentistry, Endodontics Division-UNESP-UNIV Estadual Paulista, São José dos Campos Dental School, São José dos Campos, São Paulo, Brazil.
authors.forename: Ana P M
authors.initials: AP
authors.lastname: Gomes
authors.affiliation: Department of Restorative Dentistry, Endodontic Division, Fluminense Federal University (UFF), Niteroi, Rio de Janeiro, Brazil.
authors.forename: Lilian F
authors.initials: LF
authors.lastname: Freitas
authors.affiliation: Department of Restorative Dentistry, Endodontic Division, Fluminense Federal University (UFF), Niteroi, Rio de Janeiro, Brazil.
authors.forename: Izabel C G
authors.initials: IC
authors.lastname: Camões
mesh_terms: D058491:Bacterial Load / Q000187:drug effects; D002710:Chlorhexidine / Q000008:administration & dosage*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D010485:Periapical Periodontitis / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000379:methods; D012390:Root Canal Therapy / Q000379:methods; D058408:Th1-Th2 Balance / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: C508598:IL4 protein, human; D007376:Interleukin-2; D012388:Root Canal Irrigants; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D007371:Interferon-gamma; D002710:Chlorhexidine
keywords: Disinfection; endodontics; medication; root canal