title: Experimental tooth pain elevates substance P and matrix metalloproteinase-8 levels in human gingival crevice fluid.
abstract: OBJECTIVE
  Tooth pain can induce a neurogenic inflammatory reaction in gingiva in association with local elevations of matrix metalloproteinase (MMP)-8, which is considered the major tissue destructive protease in gingival crevice fluid (GCF). The pro-inflammatory neuropeptides released by sensory nerves coordinate the activities of the immuno-effector cells and may influence the secretion of MMP-8. With this background, we studied whether experimental tooth pain can trigger changes in GCF levels of the neuropeptide substance P (SP) and MMP-8.
  
  
  METHODS
  The GCF SP levels of stimulated and non-stimulated teeth were analyzed for SP using a competitive enzyme immunoassay (EIA). The GCF MMP-8 levels were determined by quantitative immunofluorometric assay (IFMA).
  
  
  RESULTS
  Painful stimulation of the upper central incisor caused significant elevations in GCF SP and MMP-8 levels of the stimulated tooth. At the same time, the GCF SP and MMP-8 levels of non-stimulated control teeth were unchanged.
  
  
  CONCLUSIONS
  These data indicate that experimental tooth pain can induce local elevations of SP and MMP-8 levels in GCF simultaneously. This supports the possibility of a local neurogenic spread of inflammatory reactions from intrapulpal to surrounding periodontal tissues.
authors.affiliation: Institute of Dentistry, University of Turku, Finland. nina-li.avellan@helsinki.fi
authors.forename: Nina-Li
authors.initials: NL
authors.lastname: Avellán
authors.forename: Timo
authors.initials: T
authors.lastname: Sorsa
authors.forename: Taina
authors.initials: T
authors.lastname: Tervahartiala
authors.forename: Clemens
authors.initials: C
authors.lastname: Forster
authors.forename: Pentti
authors.initials: P
authors.lastname: Kemppainen
mesh_terms: D000328:Adult; D003782:Dental Pulp / Q000378:metabolism*; D004558:Electric Stimulation; D005260:Female; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000378:metabolism; D005883:Gingival Crevicular Fluid / Q000737:chemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D007180:Incisor / Q000503:physiopathology; D008297:Male; D020784:Matrix Metalloproteinase 8 / Q000032:analysis / Q000096:biosynthesis*; D020078:Neurogenic Inflammation / Q000378:metabolism*; D010147:Pain Measurement; D010865:Pilot Projects; D018709:Statistics, Nonparametric; D013373:Substance P / Q000032:analysis / Q000096:biosynthesis*; D014098:Toothache / Q000378:metabolism*
chemical_list: D013373:Substance P; D020784:Matrix Metalloproteinase 8