title: Cytokine measurements in gingival crevicular fluid and periodontal ligament: Are they correlated?
abstract: BACKGROUND
  Mechanical stress can induce molecular changes in gingival crevicular fluid (GCF) and the periodontal ligament (PDL). It is still not clear whether changes in the PDL and GCF are linked. In this study, we aimed to analyze the expression of cytokines in GCF and PDL after mechanical stress.
  
  
  METHODS
  Twenty-three healthy patients were included. The experimental group consisted of premolars subjected to a force of 0.980 N for 1, 3, 7, 14, 21, or 28 days. The contralateral teeth were the controls. GCF and PDL samples were collected at the same time points for analysis of cytokines using the cytometric bead array.
  
  
  RESULTS
  Interleukin (IL)-6 (IL-6) production was significantly elevated in the PDL on day 1 after force application. Significantly strong positive correlations between GCF and PDL in experimental group were seen on days 3 (interferon-gamma), 7 (IL-10), 14 (IL-17A), and 28 (IL-17A, tumor necrosis factor-alpha), and significantly strong negative correlation were seen on days 14 (interferon-gamma) and 21 (IL-2, IL-10).
  
  
  CONCLUSIONS
  Different patterns of IL-6 expression were seen in the PDL and GCF after mechanical stress. Despite occasional correlations between GCF and PDL, the molecular contributions of the PDL to the GCF changes could not be clearly defined by our model.
authors.affiliation: Postgraduate student, Department of Morphology, Institute of Biologic Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Davidson Fróis
authors.initials: DF
authors.lastname: Madureira
authors.affiliation: Postgraduate student, Department of Morphology, Institute of Biologic Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Janine Mayra
authors.initials: JM
authors.lastname: da Silva
authors.affiliation: Associate professor, Department of Biochemistry and Immunology, Faculty of Medicine, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Antônio Lúcio
authors.initials: AL
authors.lastname: Teixeira
authors.affiliation: Associate professor, Department of Community and Preventive Dentistry, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Mauro Henrique Nogueira Guimarães
authors.initials: MH
authors.lastname: Abreu
authors.affiliation: Associate professor, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Henrique
authors.initials: H
authors.lastname: Pretti
authors.affiliation: Associate professor, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Elizabeth Maria Bastos
authors.initials: EM
authors.lastname: Lages
authors.affiliation: Associate professor, Department of Oral Surgery and Pathology, Faculty of Dentistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. Electronic address: tarcilia@ufmg.br.
authors.forename: Tarcília Aparecida
authors.initials: TA
authors.lastname: da Silva
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000502:physiology; D001696:Biomechanical Phenomena; D002648:Child; D016207:Cytokines / Q000032:analysis*; D005260:Female; D005500:Follow-Up Studies; D005883:Gingival Crevicular Fluid / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis; D016753:Interleukin-10 / Q000032:analysis; D020381:Interleukin-17 / Q000032:analysis; D007376:Interleukin-2 / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D008297:Male; D016910:Orthodontic Brackets; D010513:Periodontal Ligament / Q000276:immunology*; D013314:Stress, Mechanical; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D055815:Young Adult
chemical_list: D016207:Cytokines; C508609:IL10 protein, human; C508717:IL17A protein, human; C508594:IL2 protein, human; C508598:IL4 protein, human; C508600:IL6 protein, human; D020381:Interleukin-17; D007376:Interleukin-2; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma