Tensile bond strength of single-step self-etch adhesives to Er:YAG laser-irradiated dentin.
OBJECTIVE
The purpose of this study was to evaluate the influence of Er:YAG laser irradiation on the bond strength to dentine of three single-step adhesives (AQ Bond Plus, G-Bond, and Clearfil Tri-S Bond), and one two-step self-etch adhesive (Clearfil Megabond) as a control.


BACKGROUND
The vast majority of the numerous reports on resin bonding to Er:YAG-lased dentine have concluded that Er:YAG laser irradiation is less effective in terms of bond strength, because of the sub-surface damage it produces. However, its effect in combination with single-step adhesives on bonding to dentine remains to be clarified.


METHODS
Eighty bovine incisors were ground with silicon carbide paper to obtain a flat dentine surface, which 40 were irradiated with an Er:YAG laser. Both lased and unlased dentine was bonded to a resin composite with each adhesive. Tensile bond strength was determined after 24 h of storage in water at 37 degrees C. Failure patterns after tensile bond testing was analyzed by scanning electron microscopy.


RESULTS
The two-step self-etch adhesive (Clearfil Megabond) showed the highest bond strength to unlased dentine, but was significantly less effective on lased dentine than the three single-step adhesives. On the other hand, AQ Bond Plus produced an effective bond strength to both lased and unlased dentine, perhaps due to its low viscosity.


CONCLUSIONS
The single-step adhesives tested in this study were as effective in combination with Er:YAG-lased dentine as the two-step self-etch adhesive.
Kameyama
Atsushi
A
Department of Operative Dentistry, Tokyo Dental College, Chiba, Japan. kameyama@tdc.ac.jp
Aizawa
Koya
K
Kato
Junji
J
Hirai
Yoshito
Y
D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003804:Dentin / Q000528:radiation effects*; D017220:Dentin-Bonding Agents; D066298:In Vitro Techniques; D053844:Lasers, Solid-State; D008689:Methacrylates; D019279:Resin Cements; D013718:Tensile Strength / Q000528:radiation effects*
C453842:AQ bond; C515604:Clearfil Tri-S Bond; D017220:Dentin-Bonding Agents; C498353:G-Bond; D008689:Methacrylates; D019279:Resin Cements