title: [Effect of casein phosphopeptide-amorphous calcium phosphate on the stability of resin-dentin bonds against pH cycling].
abstract: OBJECTIVE
  To investigate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the stability of resin-dentin bonds against pH cycling.
  
  
  METHODS
  Resin-bonded dentin specimens were prepared following manufacturers' instructions, and randomly divided into 3 groups. Among them, 2 groups experienced pH cycling, in which specimens applied CPP-ACP or distilled and deionized water (DDW) on the bonding interface, respectively. Microtensile bond strength (muTBS) testing, failure mode analysis, micromorphological and nanoleakage evaluation of bonding interface and elemental analysis within hybrid layer were performed after 15 days pH cycling. The other group was tested immediately after specimens' preparation without pH cycling.
  
  
  RESULTS
  No significant differences were found in muTBS between no pH cycling and pH cycling/CPP-ACP group. Their muTBS were both significantly higher than that of pH cycling/DDW group (P < 0.05). Mixed fractures were the most prevalent failure mode. The quality of hybrid layer in pH cycling/CPP-ACP group was better than that of pH cycling/DDW group, and the nanoleakage was also less severe. Comparing with pH cycling/DDW group, the atomic percentages of Ca in the other two groups were both significantly higher, while those of Ag were statistically lower (P < 0.05).
  
  
  CONCLUSIONS
  Local application of CPP-ACP can promote the stability of resin-dentin bonding interface against pH cycling and prolong bonding degeneration.
authors.affiliation: Dept. of Prosthodontics, Dept. of Stomatology, Xi'an Medical University, Xi'an 710021, China.
authors.forename: Chengfang
authors.initials: C
authors.lastname: Tang
authors.forename: Qi
authors.initials: Q
authors.lastname: Dou
authors.forename: Ruirui
authors.initials: R
authors.lastname: Liu
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Chai
authors.forename: Lijuan
authors.initials: L
authors.lastname: Shen
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
authors.forename: Jihua
authors.initials: J
authors.lastname: Chen
mesh_terms: D002130:Calcium Phosphates; D002364:Caseins; D001840:Dental Bonding; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D010748:Phosphopeptides; D019279:Resin Cements
chemical_list: D002130:Calcium Phosphates; D002364:Caseins; D017220:Dentin-Bonding Agents; D010748:Phosphopeptides; D019279:Resin Cements; C519480:amorphous calcium phosphate; C447032:casein phosphopeptide-amorphous calcium phosphate nanocomplex