Microtensile bond strength and interfacial characterization of 11 contemporary adhesives bonded to bur-cut dentin.
OBJECTIVE
This study evaluated mechanically and ultra-morphologically 11 different adhesive systems bonded to dentin.


METHODS
The microtensile bond strength (microTBS) of 11 contemporary adhesives, including two three-step etch&rinse, three two-step etch&rinse, two two-step self-etch and four one-step self-etch adhesives to dentin, were measured. The resultant interfacial ultra-structure at dentin was characterized by transmission electron microscopy (TEM). Human third molars had their superficial dentin surface exposed, after which a standardized smear layer was produced using a medium-grit diamond bur. The selected adhesives were applied according to their respective manufacturer's instructions for microTBS measurement after storage in water at 37 degrees C for 24 hours or for TEM interfacial characterization.


RESULTS
The microTBS varied from 11.1 to 63.6 MPa; the highest bond strengths were obtained with the three-step etch&rinse adhesives and the lowest with one-step self-etch adhesives. TEM evaluation showed very different interaction patterns, especially for the self-etch adhesives. "Mild" self-etch adhesives demineralized the dentin surface sufficiently to provide micro-mechanical retention, while preserving hydroxyapatite within the hybrid layer to enable additional chemical interaction.


CONCLUSIONS
When bonded to dentin, the adhesives with simplified application procedures (in particular, one-step self-etch adhesives) still underperform as compared to conventional three-step adhesives. "Mild" two-step self-etch adhesives that provide additional chemical bonding appear to most optimally combine bonding effectiveness with a simplified application protocol.
Sarr
Mouhamed
M
Université Cheikh Anta DIOP, Faculté de Médecine, Pharmacie et Odontologie, Dakar, Senegal.
Kane
Abdoul Wakhabe
AW
Vreven
José
J
Mine
Atsushi
A
Van Landuyt
Kirsten L
KL
Peumans
Marleen
M
Lambrechts
Paul
P
Van Meerbeek
Bart
B
De Munck
Jan
J
D000134:Acid Etching, Dental; D000268:Adhesiveness; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D016369:Smear Layer; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
C503075:Clearfil Protect Bond; C505694:Clearfil S3 Bond; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C498353:G-Bond; D008689:Methacrylates; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; C408584:Prompt L-Pop; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C532387:XP-Bond; C487957:Xeno III; C083568:Z100 composite resin; D014867:Water; D012822:Silicon Dioxide; C041330:Scotchbond; D017886:Durapatite; D015040:Zirconium