title: [The potential effect of proanthocyanidins on the stability of resin-dentin bonds against thermal cycling].
abstract: OBJECTIVE
  To investigate the potential effect of proanthocyanidins (PA), a natural cross-linker, on the stability of resin-dentin bonds against thermal cycling.
  
  
  METHODS
  Ten percent, 15% PA-based preconditioners, and 5% glutaraldehyde were prepared for the transient pretreatment of demineralized dentin before bonding. Specimens without pretreatment were used as negative controls (n = 4 teeth for each group). Microtensile bond strength, failure mode, micromorphologies of resin-dentin interface and the collagen degradation of bonded specimens after thermal cycling were evaluated.
  
  
  RESULTS
  After thermal cycling, the microtensile bond strength values of resin-dentin bond in groups pretreated with 15% PA for 120 s and 60 s [(23.09 ± 3.19) and (21.88 ± 3.49) MPa] were significantly higher than that in control group [(15.47 ± 3.78) MPa] (P < 0.05). Mixed fractures were the most prevalent failure mode. Specimens with pretreatment presented compact hybrid layer, while some narrow gaps were found in hybrid layer of non-treated specimens. Collagen biodegradation rates in groups with pretreatment were significantly lower than that in control group (P < 0.05). Among them, specimens pretreated by 15% PA preconditioner for 120 s exhibited the lowest biodegradation rates [(0.316 ± 0.019) mg/g].
  
  
  CONCLUSIONS
  The application of natural cross-linker PA on demineralized dentin reduced the bond degradation against aging by thermal cycling, and can be helpful to create more durable bonds to dentin.
authors.affiliation: Department of Prosthodontics, College of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Rui-rui
authors.initials: RR
authors.lastname: Liu
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
authors.forename: San-jun
authors.initials: SJ
authors.lastname: Zhao
authors.forename: Fang
authors.initials: F
authors.lastname: Li
authors.forename: Li-juan
authors.initials: LJ
authors.lastname: Shen
authors.forename: Ji-hua
authors.initials: JH
authors.lastname: Chen
mesh_terms: D003094:Collagen / Q000378:metabolism; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D044945:Proanthocyanidins / Q000494:pharmacology*; D019279:Resin Cements; D013696:Temperature; D013718:Tensile Strength / Q000187:drug effects*
chemical_list: D017220:Dentin-Bonding Agents; D044945:Proanthocyanidins; D019279:Resin Cements; D003094:Collagen