Placement Agitation Effect on Bond Strength of Three Self-Etching Adhesives

The newest bonding agents are self-etching materials, which eliminate etching and rinsing steps.  Although simpler to apply, questions have been raised about their enamel bond. Agitation and application time could influence enamel bonding. Purpose:  To measure the bond strength of three self-etching bonding agents with and without agitation at times, 0, 10, 20 and 30 sec.    Methods:  180 extracted caries-free human teeth were wet ground to 600 grit to obtain a flat enamel surface and divided into 18 equal groups. Three bonding agents, Clearfil SE Bond (Kuraray), Xeno III (Dentsply) and AdheSE (Vivadent) were applied using 3 application times with and without agitation. After the self-etching bonding agent had been applied and cured for 10 seconds (Xeno III and Clearfil SE) or 20 seconds (AdheSE) with Avante Jeneric Pentron, output 600mW/cm², a two mm column of composite resin Z-100 (A2-Shade) was applied and cured for 40 seconds.  The samples were stored in distilled water at room temperature for at least 48 hours, placed in an Instron testing machine model 4411 and loaded in shear until failure at a 1 mm/min crosshead speed. Results: The data was converted to MPa and analyzed with 3 factor ANOVA and Tukey HSD tests for intergroup differences (p=. 05). AdheSE had significantly lower bonds (p<0.0001). Agitation did not significantly affect bond strength (p=.7).

Mean SBS (MPa)	Time Sec	10			20		30
Bonding	Agitate	Yes		No	Yes	No	Yes	No
Clearfil SE		20±4		22.9±6	21.5±5	19.1±5	23.2±6	20.7±5
Xeno III		14.6±4		12.9±5	15.9±4	20.4±5	17.3±7	17.7±3
AdheSE		12.8±4		10.7±4	13.1±3	12±6	14.1±4	14±3

Conclusions: Agitation produces no statistically significant difference in enamel bond strength with 3 self-etching adhesives.