Effect of double-application of all-in-one adhesives on dentin bonding.
OBJECTIVE
To evaluate the effect of double-application of all-in-one adhesives using the micro-shear bond test.


METHODS
The occlusal surfaces of extracted human third molars were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. Three commercially available and one experimental bonding system were used in this study: Adper Prompt L-Pop (APL, 3M ESPE), REACTMER BOND (RB, Shofu), XENO III (Xeno, Dentsply-Sankin) and newly developed OBF-2 (OB2, Tokuyama Dental). These adhesives were applied on the dentin surfaces by either the manufacturers' instructions or by an experimental method (single-application or double-application). Resin composite was then placed and light-cured for 40s. After 24h immersion in water, a micro-shear bond test was carried out and the fractured dentin surfaces were observed microscopically. The data were analyzed by one-way ANOVA and Tukey's HSD tests (p<0.05).


RESULTS
The mean bond strengths of APL, RB, Xeno and OB2 with single-application were 22.7, 28.3, 30.3 and 34.6MPa, respectively. The mean bond strengths of APL, RB, Xeno and OB2 with double-application were 29.5, 27.2, 29.6 and 32.5MPa, respectively. There were no statistically significant differences in micro-shear bond strengths between the single- and double-application methods for each adhesive system (p>0.05). The morphological observation of the fractured dentin surfaces revealed differences between the single- and double-application groups especially for APL and OB2.


CONCLUSIONS
Micro-shear bond strengths of all-in-one adhesives in this study showed no statistically significant differences between the single-application and the double-application method.
Nakaoki
Yasuko
Y
Cariology, Operative Dentistry and Endodontology, Department of Oral Health Science, Graduate School of Dental Medicine, Hokkaido University, North 13 West 7, Sapporo 060-8586, Japan. ynakaoki@den.hokudai.ac.jp
Sasakawa
Wataru
W
Horiuchi
Seiko
S
Nagano
Futami
F
Ikeda
Takatsumi
T
Tanaka
Toru
T
Inoue
Satoshi
S
Uno
Shigeru
S
Sano
Hidehiko
H
Sidhu
Sharanbir K
SK
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000008:administration & dosage / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D010755:Organophosphates / Q000008:administration & dosage / Q000737:chemistry*; D033081:Shear Strength
C489661:Adper Prompt Self-Etch; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D010755:Organophosphates; C487957:Xeno III; C447779:reactmer bond; D017438:Bisphenol A-Glycidyl Methacrylate