Abstract: | Chemical substances used during biomechanical preparation of root canals can alter
the composition of dentin surface and affect the interaction with restorative
materials.ObjectiveThe purpose of this study was to evaluate the microtensile bond strength
(µTBS) of a self-etching adhesive system to dentin irrigated with sodium
hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (eDTA).Material and MethodsThirty human third molars were sectioned 3 mm below the occlusal surface, polished
with 600- to 1200-grit silicon carbide papers, and randomly divided into 3 groups:
G1 (control): no irrigating solution; G2: 1% NaOCl; and G3: 1% NaOCl followed by
the application of 17% eDTA. The specimens received the self-etching adhesive
system (XeNO III - Dentsply), restored with microhybrid composite resin (Z250 - 3M
ESPE), sectioned and trimmed to create 4 hourglass-shaped slabs of each tooth. The
slabs were tested in microtensile strength in a universal testing machine (emic DL
2000) at a crosshead speed of 0.5 mm/min until fracture. The results were analyzed
statistically by ANOVA and Newman-Keuls test.ResultsMean µTBS values and standard deviations in MPa were: G1 = 11.89 ±
4.22; G2 = 19.41 ± 5.32; G3 = 11.34 ± 4.73. 1% NaOCl increased the
adhesive resistance significantly (p<0.001/ F=22.5763). The application of 1%
NaOCl/17% eDTA resulted in statistically similar µTBS to the control
group.ConclusionsNone of the irrigants affected negatively the µTBS of XeNO III to dentin.
The use of 1% NaOCl alone resulted in higher bond strength than the other
treatments. The combination of 1% NaOCl and 17% eDTA produced similar bond
strength to that of untreated dentin. |