Matrix metalloproteinase inhibitor modulates esterase-catalyzed degradation of resin-dentin interfaces.
Assess the modulating effect of matrix metalloproteinase (MMP) inhibition on simulated human salivary enzyme (SHSE)-catalyzed degradation of interfacial fracture-toughness (FT) of self-etched and total-etched resin-dentin interfaces.



Miniature short-rod FT specimens (N=10/group) containing a resin composite bonded to human dentin, using a self-etch (Easy Bond, EB) or a total-etch (Scotchbond, SB) adhesives, were prepared with and without application of an MMP inhibitor (galardin). Specimens were non-incubated or incubated in phosphate buffered saline (PBS) or SHSE for 7, 30, 90, or 180-days. FT data were obtained using a universal testing machine. Incubation media were analyzed by high performance liquid chromatography (HPLC) for the presence of a 2,2-bis-[4-2(2-hydroxy-3-methacryloxypropoxy)phenyl]-propane (bisGMA)-derived degradation product, bis-hydroxy-propoxy-phenyl-propane (bisHPPP). Fractographic analysis was performed by scanning electron microscopy and image processing software (ImageJ). Statistical analysis was performed by ANOVA and Tukey's (p<0.05).



More bisHPPP was detected in SHSE vs. PBS for both adhesive systems (p<0.05). EB specimens yielded no difference in FT and failed preferentially in the resin after >30-days (p<0.05). SB specimens yielded lower FT values after 180-days with SHSE ±galardin vs. 0-days/no-galardin (p<0.05) and failed preferentially in the hybrid-layer after >30-days (p<0.05). Galardin mildly modulated the change in fracture mode for both systems.



Esterase-catalyzed degradation of total-etch interfaces is modulated by MMP-inhibition, however, self-etch interfaces possess greater biostability under simulated intra-oral conditions, regardless of MMP inhibition. This could be related to different chemical compositions and/or mode of adhesion.
Institute of Biomaterials and Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Rosebrugh Building, Room 407, 164 College Street, Toronto, ON M5S 3G9, Canada. Electronic address: kserkies@aforensics.ca.
Kyle B
KB
Serkies
Dental Research Institute, Faculty of Dentistry, University of Toronto, Dentistry Building, Room 464, 124 Edward Street, Toronto, ON M5G 1G6, Canada.
Reena
R
Garcha
Dental Research Institute, Faculty of Dentistry, University of Toronto, Dentistry Building, Room 464, 124 Edward Street, Toronto, ON M5G 1G6, Canada. Electronic address: laura.tam@dentistry.utoronto.ca.
Laura E
LE
Tam
Dental Research Institute, Faculty of Dentistry, University of Toronto, Dentistry Building, Room 464, 124 Edward Street, Toronto, ON M5G 1G6, Canada. Electronic address: Grace.desouza@dentistry.utoronto.ca.
Grace M
GM
De Souza
Institute of Biomaterials and Biomedical Engineering, Faculty of Applied Science and Engineering, University of Toronto, Rosebrugh Building, Room 407, 164 College Street, Toronto, ON M5S 3G9, Canada; Dental Research Institute, Faculty of Dentistry, University of Toronto, Dentistry Building, Room 464, 124 Edward Street, Toronto, ON M5G 1G6, Canada. Electronic address: Yoav.Finer@dentistry.utoronto.ca.
Yoav
Y
Finer
D001840:Dental Bonding; D003804:Dentin; D017220:Dentin-Bonding Agents; D004950:Esterases / Q000378:metabolism*; D006801:Humans; D008422:Materials Testing; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength
D017220:Dentin-Bonding Agents; D061965:Matrix Metalloproteinase Inhibitors; D019279:Resin Cements; D004950:Esterases
Biodegradation; Composite resin; Esterases; Fractography; Galardin; Hydrolysis; Interfacial fracture toughness; Matrix metalloproteinases (MMPs); Resin–dentin interface; Self-etch adhesive; Total-etch adhesive