title: Effect of polyacrylic acid on dentin protease activities.
abstract: OBJECTIVE
  This study tested whether treatment of demineralized dentin with polyacrylic acid (PAA) has any activatory or inhibitory activity on dentin matrix metalloproteinases (MMP)s or cathepsin K (CAT-K).
  
  
  METHODS
  Dentin beams (1mm×2mm×6mm; n=10) were completely demineralized with EDTA. After initial dry mass assessment, the beams were dipped into 37% phosphoric acid (PA), PA+2% benzalkonium chloride (BAC), PA+2% chlorhexidine digluconate (CHX), 10% PAA, PAA+BAC or PAA+CHX for 20s. Demineralized beams without treatment served as control. All beams were incubated in simulated body fluid (SBF) for 1 week and the dry mass loss was evaluated. Aliquots of SBF were used to analyze solubilized telopeptide fragments using ICTP as indicator of MMP-mediated collagen degradation and CTX for CAT-K-mediated degradation. Additional demineralized beams (n=10) were used to measure the influence of different chemical treatments on total MMP activity of EDTA-demineralized dentin using generic MMP assay. Data were analyzed by ANOVA (α=0.05).
  
  
  RESULTS
  Dry mass loss ranged from 6% (PA) to 2% for (PA-BAC) or (PAA-BAC) (p<0.05). ICTP release of PAA-treated group was significantly higher (p<0.05) than the control, and not significantly different from the PA group (p>0.05). PA+CHX or PAA+CHX and PAA+BAC showed significantly lower ICTP than PA or PAA groups (p<0.05). CAT-K activity increased significantly after 10% PAA treatment compared to control (p<0.05) or to PA postreatment.
  
  
  CONCLUSIONS
  Demineralized dentin treated with 10% polyacrylic acid activated CAT-K more than 37% phosphoric acid; 2% chlorhexidine digluconate seems to be a better inhibitor of MMPs and CAT-K than 2% benzalkonium chloride.
authors.affiliation: Department of Restorative Dentistry, Gazi University, Faculty of Dentistry, Ankara, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Ozcan
authors.affiliation: Finnish Doctoral Program in Oral Sciences (FINDOS) University of Turku, Institute of Dentistry, Turku, Finland; Department of Restorative Dentistry and Cariology and Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland.
authors.forename: R
authors.initials: R
authors.lastname: Seseogullari-Dirihan
authors.affiliation: Department of Restorative Dentistry, Gazi University, Faculty of Dentistry, Ankara, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Uctasli
authors.affiliation: College of Dental Medicine, Georgia Regents University, Augusta, Georgia, USA.
authors.forename: F R
authors.initials: FR
authors.lastname: Tay
authors.affiliation: College of Dental Medicine, Georgia Regents University, Augusta, Georgia, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Pashley
authors.affiliation: Department of Restorative Dentistry and Cariology and Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland; Turku University Hospital, TYKS, University of Turku, Turku, Finland. Electronic address: arztez@utu.fi.
authors.forename: A
authors.initials: A
authors.lastname: Tezvergil-Mutluay
mesh_terms: D000180:Acrylic Resins / Q000494:pharmacology*; D001548:Benzalkonium Compounds / Q000494:pharmacology; D056657:Cathepsin K / Q000378:metabolism*; D002710:Chlorhexidine / Q000031:analogs & derivatives / Q000494:pharmacology; D003094:Collagen / Q000187:drug effects; D003804:Dentin / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008963:Molar; D010756:Phosphoric Acids / Q000494:pharmacology; D017001:Tooth Demineralization
chemical_list: D000180:Acrylic Resins; D001548:Benzalkonium Compounds; D010756:Phosphoric Acids; C006903:carbopol 940; D003094:Collagen; C030242:phosphoric acid; D056657:Cathepsin K; D020782:Matrix Metalloproteinases; C010882:chlorhexidine gluconate; D002710:Chlorhexidine
keywords: Cysteine cathepsins; Degradation; Dentin; Matrix metalloproteinase; Polyacrylic acid