Micromorphological changes in resin-dentin bonds after 1 year of water storage.
The purpose of this study was to evaluate the degradation of resin-dentin bonds after 1 year of water storage. Resin-dentin-bonded specimens were prepared with the use of an adhesive resin system (One-Step: Bisco). Half of the experimental specimens were sectioned perpendicular to the adhesive interface to produce a beam (adhesive area: 0.9 mm(2)) before being stored in distilled water at 37 degrees C for 1 year. The remaining half of the bonded specimens were sectioned into beams of similar dimensions after 1 year of water storage. Additional bonded specimens that had been stored in water for 24 h before sectioning into beams were used as controls. The beams in the two experimental groups and the control group were subjected to microtensile bond testing. Fractography was performed on all fractured beams with the use of FE-SEM. There were significant (p <.05) differences in bond strength among the control specimens (55.9 +/- 12.9 MPa), specimens that had been sectioned into beams after water storage (68.9 +/- 18.6 MPa), and specimens that had been sectioned into beams before water storage (28.1 +/- 9.3 MPa). Fractography revealed that the resin material was gradually extracted from the periphery to the center portion of the beam. This probably accounted for the decrease in bond strength after 1 year of water storage.
Department of Operative Dentistry and Endodontics, School of Dentistry, Iwate Medical University, Morioka, Japan. masanori-h@mue.biglobe.ne.jp
Masanori
M
Hashimoto
Hiroki
H
Ohno
Hidehiko
H
Sano
Franklin R
FR
Tay
Masayuki
M
Kaga
Yoshiyuki
Y
Kudou
Haruhisa
H
Oguchi
Yoshima
Y
Araki
Minoru
M
Kubota
D001641:Bicuspid; D017220:Dentin-Bonding Agents / Q000592:standards*; D019544:Equipment Failure Analysis; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000592:standards; D012996:Solutions; D013048:Specimen Handling; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014867:Water
D017220:Dentin-Bonding Agents; D019279:Resin Cements; D012996:Solutions; D014867:Water