title: Effect of pretreatment with collagen crosslinkers on dentin protease activity.
abstract: OBJECTIVE
  This study evaluated the effect of dentin pretreatment with collagen crosslinkers on matrix metalloproteinase (MMP) and cathepsin K mediated collagen degradation.
  
  
  METHODS
  Dentin beams (1mm×2mm×6mm) were demineralized in 10% H3PO4 for 24h. After baseline measurements of dry mass, beams were divided into 11 groups (n=10/group) and, were pretreated for 5min with 1% glutaraldehyde (GA); 5% GA; 1% grape-seed extract (GS); 5% GS; 10% sumac (S); 20μM curcumin (CR); 200μM CR; 0.l% riboflavin/UV (R); 0.5% R; 0.1% riboflavin-5-phosphate/UV (RP); and control (no pretreatment). After pretreatment, the beams were blot-dried and incubated in 1mL calcium and zinc-containing medium (CM, pH 7.2) at 37°C for 3, 7 or 14 days. After incubation, dry mass was reassessed and aliquots of the incubation media were analyzed for collagen C-telopeptides, ICTP and CTX using specific ELISA kits. Data were analyzed by repeated-measures ANOVA.
  
  
  RESULTS
  The rate of dry mass loss was significantly different among test groups (p<0.05). The lowest 14 day mean dry mass loss was 6.98%±1.99 in the 200μM curcumin group compared to control loss of dry mass at 32.59%±5.62, p<0.05, at 14 days. The ICTP release over the incubation period (ng/mg dry dentin) ranged between 1.8±0.51 and 31.8±1.8. CTX release from demineralized beams pretreated with crosslinkers was significantly lower than CM (5.7±0.2ng/mg dry dentin).
  
  
  CONCLUSIONS
  The results of this study indicate that collagen crosslinkers tested in this study are good inhibitors of cathepsin K activity in dentin. However, their inhibitory effect on MMP activity was highly variable.
authors.affiliation: Finnish Doctoral Program in Oral Sciences (FINDOS) University of Turku, Institute of Dentistry, Turku, Finland; Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland. Electronic address: dirose@utu.fi.
authors.forename: R
authors.initials: R
authors.lastname: Seseogullari-Dirihan
authors.affiliation: Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland; Department of Restorative Dentistry and Endodontics, Institute of Dentistry, Turku, Finland.
authors.forename: M M
authors.initials: MM
authors.lastname: Mutluay
authors.affiliation: Department of Biomaterials University of Turku, Institute of Dentistry, Turku, Finland.
authors.forename: P
authors.initials: P
authors.lastname: Vallittu
authors.affiliation: School of Dentistry, Georgia Regents University, Augusta, GA, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Pashley
authors.affiliation: Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland; Department of Restorative Dentistry and Endodontics, Institute of Dentistry, Turku, Finland; Turku University Hospital, TYKS, University of Turku, Turku, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Tezvergil-Mutluay
mesh_terms: D000293:Adolescent; D002403:Cathepsins / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D003474:Curcumin / Q000494:pharmacology; D003804:Dentin / Q000201:enzymology*; D004797:Enzyme-Linked Immunosorbent Assay; D005976:Glutaral / Q000494:pharmacology; D056604:Grape Seed Extract / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008964:Molar, Third; D029045:Rhus; D012256:Riboflavin / Q000494:pharmacology; D017001:Tooth Demineralization; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D056604:Grape Seed Extract; D003094:Collagen; D002403:Cathepsins; D020782:Matrix Metalloproteinases; D003474:Curcumin; D005976:Glutaral; D012256:Riboflavin
keywords: Collagen crosslinker; Cysteine cathepsins; Dentin; Gluteraldehyde; Matrix metalloproteinase