title: Hydrolytic stability of one-step self-etching adhesives bonded to dentin.
abstract: OBJECTIVE
  To evaluate the hydrolytic stability of three one-step self-etching adhesives (1-SEAs) bonded to dentin through bond strength testing and ultra-morphological interfacial analysis before and after long-term thermocycling.
  
  
  METHODS
  Eighteen flattened mid-coronal dentin surfaces of extracted human molars were subjected to bonding treatment using three 1-SEAs (Clearfil S3 Bond, Kuraray (S3), G-Bond, GC (GB), Absolute, Dentsply-Sankin (AB)), after which the bonded surfaces were built up with composite. After storage overnight at 37°C, the specimens were sectioned into slabs and further trimmed into an hourglass shape with an interface area of approximately 1 mm2. The specimens were left untouched (control) or were thermocycled for 100,000 cycles. The microtensile bond strength (μTBS) was measured and the ultrastructure of the adhesive/dentin interface characterized using transmission electron microscopy (TEM).
  
  
  RESULTS
  Long-term thermocycling significantly decreased the μTBS of all one-step adhesives tested (p < 0.05, one way ANOVA and Games-Howell test). TEM revealed a similar interfacial ultrastructure before and after thermocycling for S3. For GB, many voids were observed at the interface after 100,000 thermocycles. Regarding AB, collagen fibrils could no longer be clearly observed upon staining, while the adjacent unaffected dentin was rich in voids.
  
  
  CONCLUSIONS
  The bond strength and ultramorphological data demonstrated that the bond of 1-SEAs to dentin degrades with time, although the degree of degradation is obviously material dependent.
authors: Department of Restorative Dentistry, Division of Oral Health Science, Hokkaido University Graduate School of Dental Medicine, Sapporo, Japan. anri@den.hokudai.ac.jp
authors: Anri
authors: A
authors: Fukuoka
authors: Kenichi
authors: K
authors: Koshiro
authors: Satoshi
authors: S
authors: Inoue
authors: Yasuhiro
authors: Y
authors: Yoshida
authors: Toru
authors: T
authors: Tanaka
authors: Takatsumi
authors: T
authors: Ikeda
authors: Kazuomi
authors: K
authors: Suzuki
authors: Hidehiko
authors: H
authors: Sano
authors: Bart Van
authors: BV
authors: Meerbeek
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000704:Analysis of Variance; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents; D006801:Humans; D006868:Hydrolysis; D008422:Materials Testing; D008689:Methacrylates; D046529:Microscopy, Electron, Transmission; D008963:Molar; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: C514346:Absolute adhesive; C505694:Clearfil S3 Bond; D017220:Dentin-Bonding Agents; C498353:G-Bond; D008689:Methacrylates; D019279:Resin Cements