Self-etching adhesives as pre-conditioner for bonding to NaOCl-treated dentin

Self-etching adhesives as pre-conditioner for bonding to NaOCl-treated dentin.

ABSTRACT

Objectives: The purpose of this study was to evaluate effect of pre-conditioning with self-etching adhesive systems on bond strengths to normal and sodium hypochlorite-treated dentin.

Methods: The occlusal surfaces of forty-eight extracted human third molars were horizontally cut to expose sound dentin. The dentin surfaces of the teeth were treated with 6% NaOCl aqueous solution for 30 sec or none, and then rinsing off with water for 10 sec and air drying. 1-step self-etching adhesive systems (Clearfil S³ Bond ND, MTB-200, Bond Force or Xeno V) were applied to the dentin surfaces and light-cured according to the manufacture’s instruction. Before bonding procedure, half of the specimens were pre-conditioned with self-etching adhesive itself for 3 sec and rinsed off with water for 30. The other half were not pre-conditioned. Resin composite (Clearfil AP-X) crowns were built up. The bonded specimens were stored in water for 24 hours, and then subjected to the microtensile bond test at a crosshead speed of 1.0 mm/min. Data were analyzed by three-way ANOVA and t-test (p<0.05).

Results:  

Table: Microtensile bond strength of experimental groups (n=14)
Dental adhesives	Clearfil S3 Bond ND		MTB-200		Bond Force		Xeno V
Pre-conditioning	No	Yes	No	Yes	No	Yes	No	Yes
Normal dentin	52.2(4.3)A	46.7(4.3)a	51.9(4.0)B	46.4(4.1)b	34.2(4.1)C	23.6(2.5)D	40.3(4.1)E	34.2(3.8)e
NaOCl-treated dentin	46.6(4.1)a	50.9(3.8)A	45.5(4.2)b	49.8(4.4)B	26.9(4.7)c	27.5(3.8)c	34.1(3.2)e	35.6(3.4)e
Group identified by the different superscript letters are significantly different (p<0.05)

Conclusions: For Clearfil S³ Bond ND and MTB-200, the pre-conditioning with self-etching adhesives itself had effectiveness for improvement of compromised bonding to NaOCl-treated dentin, while for Bond Force and Xeno V, there were no significant differences between with and without pre-conditioning. However the pre-conditioning decreased the bond strength to sound dentin in all of these experimental adhesives.