title: A Prospective Clinical Pilot Study on the Level of Matrix Metalloproteinase-9 in Dental Pulpal Blood as a Marker for the State of Inflammation in the Pulp Tissue.
abstract: BACKGROUND
  Differentiation between reversible pulpitis (savable pulp) and irreversible inflammation of the pulp tissue (nonsavable pulp) based only on clinical and radiographic diagnoses has proven to be difficult. Pulp exposure allows for the collection of pulpal blood to quantitatively determine the level of inflammation markers or proteolytic enzymes, even with small samples. Pulpitis is associated with the invasion of neutrophil granulocytes and their release of matrix metalloproteinase-9 (MMP-9).
  
  
  METHODS
  Forty-four patients (aged 18-74 years, mean = 35 years), each with 1 tooth with carious pulp exposure presenting with different stages of pulpitis, were included in this prospective, 2-center clinical study; 26 patients presented with irreversible pulpitis (groups 3 and 4), 10 with reversible pulpitis (group 2), and 8 with completely asymptomatic teeth with deep carious lesions (group 1). Six of the 26 patients with teeth diagnosed with irreversible pulpitis had not taken any nonsteroidal anti-inflammatory drugs and were evaluated as a separate group (group 4). Partial pulpotomy and blood sample collection from the pulp chamber were performed. The total levels of MMP-9 and tissue inhibitor of metalloproteinase-1 were assessed by fluorometric and colorimetric enzyme-linked immunosorbent assays, respectively. The Mann-Whitney U test and Spearman rank correlations were used to compare the MMP-9 levels with different stages of pulpal inflammation; significance was set at .05.
  
  
  RESULTS
  The MMP-9 levels in the asymptomatic teeth (group 1) were significantly different from those in the teeth with reversible pulpitis (group 2, P = .006) or irreversible pulpitis (group 4, P < .001). A statistically significant difference was also observed between the MMP-9 levels in group 1 and group 3 (P < .001) in which the patients had taken nonsteroidal anti-inflammatory drugs.
  
  
  CONCLUSIONS
  These findings indicate that the MMP-9 levels in pulpal blood samples could be a useful ancillary diagnostic tool for distinguishing different stages of pulp tissue inflammation.
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany. Electronic address: johannes.mente@med.uni-heidelberg.de.
authors.forename: Johannes
authors.initials: J
authors.lastname: Mente
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Jelena
authors.initials: J
authors.lastname: Petrovic
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Gehrig
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Sarah
authors.initials: S
authors.lastname: Rampf
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Annemarie
authors.initials: A
authors.lastname: Michel
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Schürz
authors.affiliation: Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Pfefferle
authors.affiliation: Institute of Medical Biometry and Informatics, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Saure
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Erber
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003782:Dental Pulp / Q000098:blood supply* / Q000201:enzymology / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D011671:Pulpitis / Q000097:blood* / Q000188:drug therapy / Q000473:pathology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood; D055815:Young Adult
chemical_list: D015415:Biomarkers; C560822:TIMP1 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9
keywords: Clinical diagnosis; irreversible pulpitis; matrix metalloproteinase-9; pulp tissue inflammation; reversible pulpitis