title: The effects of aging on shear bond strength and nanoleakage expression of an etch-and-rinse adhesive on human enamel and dentin.
abstract: OBJECTIVE
  To evaluate the effects of increasing thermocycling regimens on bond strength and nanoleakage of an etch-and-rinse adhesive.
  
  
  METHODS
  Adper Single Bond (3M ESPE) was used for bonding resin composite to human enamel and dentin. Specimens were stored in water (37°C, 24 h) and subjected to thermocycling (5°C and 55°C) in five groups: 1. control (no thermal cycling), 2. 100, 3. 500, 4. 2000, or 5. 10,000 cycles. The microshear bond test was performed at a crosshead speed of 1 mm/min (n = 16). Nanoleakage specimens were immersed in silver nitrate and FE-SEM micrographs were digitally analyzed to calculate silver penetration in three samples.
  
  
  RESULTS
  The mean bond strength to enamel was not significantly affected by thermocycling. However, artificial aging decreased dentin bond strength in groups 4 and 5 compared to control. Weibull analysis indicated that the characteristic strength decreased gradually with aging in both substrates. All groups exhibited some nanoleakage, and a significant increase in silver penetration compared to the control was observed in enamel and dentin groups 2 to 5.
  
  
  CONCLUSIONS
  A nanoleakage increase was detected in an earlier stage of aging than when a significant drop in bond strength was observed, with the dentin bond being more susceptible to deterioration.
authors: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors: Ilnaz
authors: I
authors: Hariri
authors: Yasushi
authors: Y
authors: Shimada
authors: Alireza
authors: A
authors: Sadr
authors: Shizuko
authors: S
authors: Ichinose
authors: Junji
authors: J
authors: Tagami
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins; D001840:Dental Bonding; D003743:Dental Enamel / Q000502:physiology; D003763:Dental Leakage; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements; D033081:Shear Strength; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate