title: Effects of type I collagen degradation on the durability of three adhesive systems in the early phase of dentin bonding.
abstract: OBJECTIVE
  This study was designed to evaluate the effects of type I collagen degradation on the durability of three adhesive systems in the early phase of dentin bonding.
  
  
  METHODS
  Bonded dentin specimens were prepared using three different types of adhesive systems. Micro-tensile bond strength and degradation of collagen were tested before, and after 1 month or 4 months of aging in artificial saliva. The relationship between micro-tensile bond strength and collagen degradation was analyzed by calculating their Pearson's correlation coefficient.
  
  
  RESULTS
  Aging induced time-dependent reduction in micro-tensile bond strengths for all the tested adhesive systems, although such reduction for the single-step self-etching adhesive G-Bond (GB) was not statistically significant. The bond strength of the two-step self-etching primer adhesive system Clearfil SE Bond (SEB) was similar to that of the two-step etch-and-rinse self-priming adhesive system Single Bond 2 (SB), and they were both significantly reduced after one or four months of aging. A negative correlation was found between the degree of collagen degradation and magnitude of micro-tensile bond strength (r = -0.65, p = 0.003). The Pearson's correlation coefficient was 0.426, indicating that 42.6% of the aging-induced reduction in bond strength can be explained by the degradation of collagen.
  
  
  CONCLUSIONS
  In the early phase of dentin bonding, there was a negative correlation between the degree of collagen degradation and the magnitude of micro-tensile bond strength. The reduction of bond strength was accompanied by the degradation of collagen. These results provide evidence for the causative relationship between the degradation of collagen and the deterioration of dentin-adhesive interface.
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Hu
authors.affiliation: Department of Stomatology, Kunming General Hospital of Chengdu Military Command, Kunming, 650032, China.
authors.forename: Yu-hong
authors.initials: YH
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Stomatology, Kunming General Hospital of Chengdu Military Command, Kunming, 650032, China.
authors.forename: An-qi
authors.initials: AQ
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China.
authors.forename: Ji-hua
authors.initials: JH
authors.lastname: Chen
mesh_terms: D024042:Collagen Type I / Q000378:metabolism*; D003804:Dentin / Q000378:metabolism*; D003810:Dentinogenesis; D006801:Humans; D059748:Proteolysis; D013718:Tensile Strength; D013997:Time Factors; D014014:Tissue Adhesives / Q000737:chemistry
chemical_list: D024042:Collagen Type I; D014014:Tissue Adhesives