Carbodiimide inactivation of MMPs and effect on dentin bonding

The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. this study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (edc) cross-linker to inhibit matrix metalloproteinase (mmp) activity. the hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) edc pre-treatment prevents this enzymatic activity. the zymographic assay was performed on protein extracts obtained from dentin powder treated with optibond fl or scotchbond 1xt with or without 0.3m edc pre-treatment. for in situ zymography,adhesive/dentin interfaces were created with the same adhesives applied to acid-etched dentin slabs pre-treated or not with edc conditioner. zymograms revealed increased expression of dentin endogenous mmp-2 and -9 after adhesive application,while the use of edc as a primer inactivated dentin gelatinases. results of in situ zymograpy showed that hybrid layers of tested adhesives exhibited intense collagenolytic activity,while almost no fluorescence signal was detected when specimens were pre-treated with edc. the correlative analysis used in this study demonstrated that edc could contribute to inactivate endogenous dentin mmps within the hybrid layer created by etch-and-rinse adhesives. © international & american associations for dental research.