Grape seed proanthocyanidins increase collagen biodegradation resistance in the dentin/adhesive interface when included in an adhesive.
OBJECTIVE
Contemporary methods of dentin bonding could create hybrid layers (HLs) containing voids and exposed, demineralised collagen fibres. Proanthocyanidins (PA) have been shown to cross-link and strengthen demineralised dentin collagen, but their effects on collagen degradation within the HL have not been widely studied. The purpose of this study was to compare the morphological differences of HLs created by BisGMA/HEMA model adhesives with and without the addition of grape seed extract PA under conditions of enzymatic collagen degradation.


METHODS
Model adhesives formulated with and without 5% PA were bonded to the acid etched dentin. 5-μm-thick sections cut from the bonded specimens were stained with Goldner's trichrome. The specimens were then exposed to 0.1% collagenase solution for 0, 1, or 6 days. Following collagenase treatment, the specimens were analysed with SEM/TEM.


RESULTS
Staining did not reveal a difference in the HLs created with the two adhesives. SEM showed the presence of intact collagen fibrils in all collagenase treatment conditions for specimens bonded with adhesive containing PA. These integral collagen fibrils were not observed in the specimens bonded with adhesive without PA after the same collagenase treatment. TEM confirmed that the specimens containing PA still showed normal collagen fibril organisation and dimensions after treatment with collagenase solution. In contrast, disorganised collagen fibrils in the interfacial zone lacked the typical cross-banding of normal collagen after collagenase treatment for specimens without PA.


CONCLUSIONS
The presence of grape seed extract PA in dental adhesives may inhibit the biodegradation of unprotected collagen fibrils within the HL.
Green
Bradley
B
University of Missouri-Kansas City School of Dentistry, 650 E. 25th St., Kansas City, MO 64108, USA.
Yao
Xiaomei
X
Ganguly
Arindam
A
Xu
Changqi
C
Dusevich
Vladimir
V
Walker
Mary P
MP
Wang
Yong
Y
D000134:Acid Etching, Dental / Q000379:methods; D001391:Azo Compounds; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D047009:Hathewaya histolytica / Q000201:enzymology; D003094:Collagen / Q000187:drug effects / Q000648:ultrastructure*; D004396:Coloring Agents; D003432:Cross-Linking Reagents / Q000737:chemistry*; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004801:Eosine Yellowish-(YS); D056604:Grape Seed Extract / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008739:Methyl Green; D003012:Microbial Collagenase / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D063065:Organophosphonates / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D044945:Proanthocyanidins / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors; D027843:Vitis
D001391:Azo Compounds; D004396:Coloring Agents; D003432:Cross-Linking Reagents; D017220:Dentin-Bonding Agents; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D008689:Methacrylates; D063065:Organophosphonates; D010756:Phosphoric Acids; D044945:Proanthocyanidins; C454540:Scotchbond etchant; C511238:Single Bond Plus; C017768:trichrome stain; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate; D008739:Methyl Green; D003094:Collagen; C030242:phosphoric acid; D003012:Microbial Collagenase; D004801:Eosine Yellowish-(YS)