title: Effect of natural cross-linkers incorporation in a self-etching primer on dentine bond strength.
abstract: OBJECTIVE
  The aim of this in vitro study was to investigate the effect of incorporation of natural cross-linkers into the primer of a self-etching adhesive on resin-dentine bond strength.
  
  
  METHODS
  Flat dentine surfaces were prepared from extracted human molar teeth and were applied with the following self-etching primers. The 0.5% hesperidin (HPN), 0.5% chlorhexidine (CHX) or 0.5% grape seed extract (GSE) was incorporated into Clearfil SE primer (Kuraray Medical, Inc.) to formulate three experimental primers. The original SE primer served as control. Following primer application, the teeth were bonded with Clearfil SE bond, restored with resin composite and stored in water for 24 h at 37 °C. The bonded specimens were sectioned into beams and subjected to micro tensile bond testing (μTBS). Failure analysis and morphological evaluation of the dentine surfaces were performed using a scanning electron microscope (SEM). Hardness (H) and elastic modulus (EM) were measured using nano-indentation technique to examine the mechanical properties of the bonded interfaces.
  
  
  RESULTS
  One-way ANOVA showed significant differences in μTBS, H and EM among the tested and control groups (p < 0.001). Tukey post hoc test revealed that incorporation of HPN significantly increased μTBS, H and EM, when compared with the other groups (p < 0.006). The GSE-incorporated group significantly decreased μTBS, H and EM, when compared with the other groups (p < 0.006); while CHX-incorporated group did not show any statistical significant difference when compared with the control group.
  
  
  CONCLUSIONS
  Incorporation of HPN into Clearfil SE primer had a positive influence on the immediate μTBS and mechanical properties of the bonded interface.
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Science, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Tokyo 113-8549, Japan.
authors.forename: Sofiqul
authors.initials: S
authors.lastname: Islam
authors.forename: Noriko
authors.initials: N
authors.lastname: Hiraishi
authors.forename: Mohannad
authors.initials: M
authors.lastname: Nassar
authors.forename: Cynthia
authors.initials: C
authors.lastname: Yiu
authors.forename: Masayuki
authors.initials: M
authors.lastname: Otsuki
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D002710:Chlorhexidine / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000737:chemistry*; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D055119:Elastic Modulus; D056604:Grape Seed Extract / Q000737:chemistry; D006244:Hardness; D006569:Hesperidin / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D009943:Organophosphorus Compounds / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D016369:Smear Layer; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C438313:Clearfil SE Bond; D003188:Composite Resins; D003432:Cross-Linking Reagents; D056604:Grape Seed Extract; C074230:MDP adhesion promoting monomer; D008689:Methacrylates; D009943:Organophosphorus Compounds; D019279:Resin Cements; D014867:Water; C005044:hydroxyethyl methacrylate; D006569:Hesperidin; D002710:Chlorhexidine