Shear Bond Evaluation of Current Self-Etching Adhesive Systems

Introduction New generation all-in-one self-etching (SE) adhesives are promoted for dentin and enamel bonding, but reports about their performance vary. Objectives:  This study evaluates the shear bond strength (SBS) of several current SE adhesive systems.  Methods: Seven SE adhesive systems were tested in this in-vitro study: A. Bond Force (Tokuyama); B. G-Bond (GC); C. Adper L Pop (3M-ESPE); D. Xeno IV (Dentsply); E. Clearfil Tri-S Bond (Kuraray); F. Easy Bond (3M-ESPE) and G. Clearfil SE Bond (Kurary) as control. Human extracted permanent teeth were mounted into acrylic resin cylinders and sectioned to reveal either dentin or enamel. Each group was treated according to the manufacturers' instructions. Composite (Z-250, 3M-ESPE) was used in conjunction with all adhesives. The composite was placed over the tooth surface using special molds and holding clamps (Ultradent). All specimens were photopolymerized with the same light curing unit (Astralis 10 – Ivoclar). All specimens were tested in shear mode after 24 hours in water. Data was analyzed for significant differences using two way ANOVA.  Results: Mean SBS (MPa) and SD are shown in the table below:

Material	A	B	C	D	E	F	G
Enamel	31.9(4.6)	29.7(5.4)	24.8(3.5)	27.5(2.3)	30.4(3.7)	28.1(3.9)	27.9(5.4)
Dentin	32.0(3.7)	28.4(2.4)	24.3(4.4)	28.3(3.6)	32.6(6.8)	27.3(3.7)	26.9(2.8)

Conclusion: ANOVA revealed a significant difference in SBS to enamel and dentin between all materials. Post-Hoc multiple comparison test concluded that Bond Force and Clearfil Tri-S Bond generated significantly higher SBS than other groups tested, but not significantly different from each other. This study demonstrates the capability of new generation SE adhesives to yield mean SBS and variance comparable to conventional adhesives.