title: Biomodification to dentin by a natural crosslinker improved the resin-dentin bonds.
abstract: OBJECTIVE
  Transient collagen cross-linking treatment by proanthocyanidins (PA), a natural crosslinker, was proved to increase the cross-linking degree and ultimate tensile strength of demineralised dentin. The present study aimed to investigate whether transient pretreatment by PA-based preconditioner can improve the resin-dentin bonds of various etch and rinse adhesives. The influence of solvent type, PA concentration and treatment duration were examined.
  
  
  METHODS
  PA-based preconditioners were prepared by adding powdered grape seed extract, rich in PA, to various solvents at different concentrations. They were used on demineralised dentin before the application of the bonding agent. Bond strength, failure modes and degree of conversion were evaluated via microtensile testing, field emission scanning electron microscopy and Fourier transform infrared spectroscopy, respectively.
  
  
  RESULTS
  Collagen cross-linking treatment by PA-based preconditioners presented a concentration- and time-dependent increase in dentin bond strength even in reduced, clinically applicable treatment duration. PA preconditioning improved bond strength of the tested water/ethanol-based adhesive better than the water/acetone-based system. Mixed fracture was the most prevalent failure mode happened on the top of the hybrid layer in PA-pretreated specimens, whilst at the bottom in non-treated controls. The degree of conversion was not significantly affected by PA pretreatment.
  
  
  CONCLUSIONS
  Transient PA preconditioning improved resin-dentin bonds without compromise on the curing behaviours of the tested adhesives.
authors.affiliation: Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, #145 Changle Xi Road, Xi'an, 710032, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
authors.forename: Ruirui
authors.initials: R
authors.lastname: Liu
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Xiao
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Danyang
authors.initials: D
authors.lastname: Wang
authors.forename: Rui
authors.initials: R
authors.lastname: Hou
authors.forename: Jihua
authors.initials: J
authors.lastname: Chen
mesh_terms: D000096:Acetone / Q000737:chemistry; D000268:Adhesiveness; D003094:Collagen / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D000431:Ethanol / Q000737:chemistry; D005976:Glutaral / Q000494:pharmacology; D056604:Grape Seed Extract / Q000494:pharmacology*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry; D044945:Proanthocyanidins / Q000494:pharmacology*; D019279:Resin Cements / Q000737:chemistry; D012997:Solvents / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013718:Tensile Strength; D013997:Time Factors; D027843:Vitis; D014867:Water / Q000737:chemistry
chemical_list: C554641:Adper single bond 2; D003432:Cross-Linking Reagents; D003738:Dental Cements; D056604:Grape Seed Extract; C511402:Grape Seed Proanthocyanidins; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D044945:Proanthocyanidins; D019279:Resin Cements; D012997:Solvents; D014867:Water; D000096:Acetone; D000431:Ethanol; D003094:Collagen; D005976:Glutaral