Microtensile bond strength of etch-and-rinse and self-etching adhesives to intrapulpal dentin after endodontic irrigation and setting of root canal sealer.
OBJECTIVE
To evaluate the effect of endodontic irrigation regimens and calcium hydroxide root canal sealer (Sealapex) on the microtensile bond strengths (muTBS) of dual-curing resin composite (Clearfil DC Core Automix) to the intrapulpal dentin.


METHODS
Forty standardized coronal-half root canal dentin specimens obtained from human premolars were divided into 4 groups: group A, no treatment (control); group B, Sealapex; group C, NaOCl/Sealapex; group D, EDTA/NaOCl/Sealapex. After 7 days of storage in 100% relative humidity, Sealapex was removed. Dentin surfaces were bonded with adhesives, either etch-and-rinse (Single Bond) or self-etching (Clearfil SE Bond), and built up with resin composite. The bonded specimens were trimmed into an hourglass shape with a 1-mm2 cross-sectional area for microtensile testing (n = 20). The muTBS to intrapulpal dentin was analyzed using two-way ANOVA and Dunnett's TC test. Two teeth of each group were prepared for micromorphological analysis of dentin surface.


RESULTS
The root canal sealer with or without endodontic irrigation significantly affected the bond strengths of resin composite to intrapulpal dentin compared with the control group (p < 0.05). There were no significant differences in muTBS of each experimental group between etch-and-rinse and self-etching adhesives (p > 0.05). The dentin surface was covered with a mud-like material after sealer application for 7 days.


CONCLUSIONS
The root canal sealer reduced the muTBS of dual-curing resin composite with etch-and-rinse and self-etching adhesive systems to intrapulpal dentin. Treatment with EDTA followed by NaOCI prior to obturation caused an additional reduction in muTBS of both adhesive systems to intrapulpal dentin.
Wattanawongpitak
Nipaporn
N
Department of Restorative Dentistry, Faculty of Dentistry, Naresuan University, Tambon Thaphoe, Amphor Muang, Phitsanulok, Thailand. nipapornhw@gmail.com
Nakajima
Masatoshi
M
Ikeda
Masaomi
M
Foxton
Richard M
RM
Tagami
Junji
J