title: Matrix metalloproteinase-8 and substance P levels in gingival crevicular fluid during endodontic treatment of painful, nonvital teeth.
abstract: OBJECTIVE
  The aim of this study was to investigate levels of matrix metalloproteinase-8 (MMP-8) and substance P (SP) in gingival crevicular fluid (GCF) during root canal treatment (RCT) of nonvital teeth.
  
  
  METHODS
  Patients scheduled for nonsurgical RCT were prospectively selected; all patients provided informed consent. GCF samples were collected from teeth scheduled for RCT and their contralateral teeth across 3 different time periods. MMP-8 and SP levels were measured using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using a mixed model analysis and the Pearson correlation analysis.
  
  
  RESULTS
  Patients' subjective pain levels were significantly related to both MMP-8 and SP levels. MMP-8 and SP levels in GCF were decreased during RCT, and they showed a positive correlation with each other (P < .05).
  
  
  CONCLUSIONS
  This study demonstrated that periradicular inflammation of endodontic origin can elevate SP and MMP-8 levels in GCF.
authors.affiliation: Department of Conservative Dentistry, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Su-Jung
authors.initials: SJ
authors.lastname: Shin
authors.forename: Woocheol
authors.initials: W
authors.lastname: Lee
authors.forename: Jae-Il
authors.initials: JI
authors.lastname: Lee
authors.forename: Seung-Ho
authors.initials: SH
authors.lastname: Baek
authors.forename: Kee-Yeon
authors.initials: KY
authors.lastname: Kum
authors.forename: Won-Jun
authors.initials: WJ
authors.lastname: Shon
authors.forename: Kwang-Shik
authors.initials: KS
authors.lastname: Bae
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D005883:Gingival Crevicular Fluid / Q000737:chemistry*; D006801:Humans; D018836:Inflammation Mediators / Q000032:analysis; D008297:Male; D020784:Matrix Metalloproteinase 8 / Q000032:analysis*; D018377:Neurotransmitter Agents / Q000032:analysis*; D010147:Pain Measurement; D010485:Periapical Periodontitis / Q000378:metabolism; D011446:Prospective Studies; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012389:Root Canal Obturation / Q000379:methods; D018915:Root Canal Preparation / Q000295:instrumentation; D012390:Root Canal Therapy; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013373:Substance P / Q000032:analysis*; D019553:Tooth, Nonvital / Q000378:metabolism / Q000628:therapy*; D014098:Toothache / Q000378:metabolism
chemical_list: D018836:Inflammation Mediators; D018377:Neurotransmitter Agents; D012388:Root Canal Irrigants; D013373:Substance P; D012973:Sodium Hypochlorite; C488762:MMP8 protein, human; D020784:Matrix Metalloproteinase 8