title: Inhibition of endogenous dentin matrix metalloproteinases by ethylenediaminetetraacetic acid.
abstract: BACKGROUND
  Endogenous dentin matrix metalloproteinases (MMPs) contribute to extracellular collagen matrix degradation in hybrid layers after adhesive dentin bonding procedures. Endodontic irrigants, including chlorhexidine and ethylenediaminetetraacetic acid (EDTA), might help protect the hybrid layer from this process. The objective of the present study was to determine the exposure time necessary for EDTA to inactivate endogenous MMP activity in human dentin.
  
  
  METHODS
  Dentin beams (2 × 1 × 3 mm) were prepared from mid-coronal dentin of extracted third molars. The beams were demineralized in 10 wt% phosphoric acid, which also activated endogenous MMPs, and were divided into 4 experimental groups on the basis of exposure time to 17% EDTA (0, 1, 2, or 5 minutes). A generic colorimetric MMP assay measured MMP activity via absorbance at 412 nm. Data were evaluated by Kruskal-Wallis analysis of variance, followed by Dunn pair-wise comparisons at α = 0.05.
  
  
  RESULTS
  All exposure times resulted in significant inhibition (P < .001) compared with unexposed controls. Specifically, percent inhibition for 1-, 2-, and 5-minute exposure times was 55.1% ± 21.5%, 72.8% ± 11.7%, and 74.7% ± 19.7%, respectively.
  
  
  CONCLUSIONS
  Seventeen percent EDTA significantly inhibits endogenous MMP activity of human dentin within 1-2 minutes. This might minimize hybrid layer degradation after resin bonding procedures in the root canal space.
authors.affiliation: United States Army Dental Activity, Fort Gordon, Georgia, USA.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Thompson
authors.forename: Kelli
authors.initials: K
authors.lastname: Agee
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Sidow
authors.forename: Kathleen
authors.initials: K
authors.lastname: McNally
authors.forename: Kimberly
authors.initials: K
authors.lastname: Lindsey
authors.forename: James
authors.initials: J
authors.lastname: Borke
authors.forename: Mohammed
authors.initials: M
authors.lastname: Elsalanty
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D002863:Chromogenic Compounds; D003124:Colorimetry; D003804:Dentin / Q000187:drug effects / Q000201:enzymology*; D004492:Edetic Acid / Q000494:pharmacology*; D006801:Humans; D008422:Materials Testing; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases / Q000032:analysis; D010756:Phosphoric Acids / Q000737:chemistry; D012388:Root Canal Irrigants / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D002863:Chromogenic Compounds; D061965:Matrix Metalloproteinase Inhibitors; D010756:Phosphoric Acids; D012388:Root Canal Irrigants; D004492:Edetic Acid; C030242:phosphoric acid; D020782:Matrix Metalloproteinases; D020780:Matrix Metalloproteinase 9