Effect of water storage on the bonding effectiveness of 6 adhesives to Class I cavity dentin.
Adhesive-dentin interfaces degrade with time. This study determined the effect water storage may have on the bonding effectiveness of adhesives to occlusal Class I cavity-bottom dentin. Six adhesives, all representing contemporary classes of adhesives, were applied: a 3-step (OptiBond FL, Kerr) and 2-step (Scotchbond 1*, 3M ESPE) etch-and-rinse adhesive, a 2-step (Clearfil SE, Kuraray) and 1-step (Adper prompt, 3M ESPE) self-etch adhesive and a 2-step (FujiBond LC, GC) and 1-step (Reactmer, Shofu) resin-modified glass-ionomer adhesive. Bonding effectiveness was assessed by microtensile bond strength testing (MTBS) and electron microscopy (Feg-SEM and TEM). The MTBS was determined after 1 day and 1 year water storage of the entire restored cavity (indirect exposure of the adhesive-dentin interface to water) and prepared microTBS-beams (direct exposure of the adhesive-dentin interface to water). The hypotheses tested were: (1) resin-dentin bonds formed at the bottom of Class I cavities resist 1-year water storage and (2) an adjacent composite-enamel bond protects the composite-dentin bond against degradation. Non-parametric Kruskal-Wallis analysis statistically analyzed the microTBSs. The first hypothesis was rejected, as only the microTBS of OptiBond FL and Clearfil SE did not significantly decrease after 1-year direct and/or indirect water storage. The second hypothesis was corroborated, as the bonding effectiveness of most simplified adhesives (Scotchbond 1, Adper Prompt, FujiBond LC and Reactmer) approached 0 (because of the frequent pre-testing failures) after 1-year direct water exposure. The second hypothesis concluded that the 3-step etch-and-rinse adhesive must still be regarded the "gold standard." Though microTBS decreased significantly, Clearfil SE, as a 2-step self-etch adhesive, was the only simplified adhesive to perform reliably after 1-year direct water exposure.
De Munck
Jan
J
Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-facial Surgery, Catholic University of Leuven, Belgium. jan.demunck@med.kuleuven.be
Shirai
Kenichi
K
Yoshida
Yasuhiro
Y
Inoue
Satoshi
S
Van Landuyt
Kirsten
K
Lambrechts
Paul
P
Suzuki
Kazuomi
K
Shintani
Hideaki
H
Van Meerbeek
Bart
B
D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000145:classification*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry*
C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; C469607:OptiBond FL; C408584:Prompt L-Pop; D019279:Resin Cements; C447779:reactmer bond; D014867:Water; C084541:Fuji glass-ionomer lining cement; C041330:Scotchbond