Comparison of the adhesive strength of self etching adhesives at different dentin thickness

HUANG Lan-lan; YI Hong; LIU Xiao-min

doi:10.15956/j.cnki.chin.j.conserv.dent.2018.03.006

Abstract：AIM:To evaluate the adhesive strength of the self etching adhesives.METHODS:24 freshly ex-tracted premolars were selected,and the crown enamel was removed. The superficial dentin was exposed and the teeth were divided into 3 groups randomly(n=8). The dentin surfaces were bonded with:OptiBond Versa(OV),Clearfil SE Bond(SE) and G Bond (GB) according to the manufacturers′ directions respectively. Then P60 composite build-up was made for all samples. After storage for 24 hours in water at 37 ℃. cylindrical specimens with an area of 1.0 mm2 perpendicular to the dentin surface of the samples were prepared using a slow-speed slicer. The remaining dentin thick-ness(RDT) was measured to assess the superficial dentin group (RDT≥3 mm) and the deep dentin group (RDT≤2 mm).Microtensile bond strength measurements were evaluated. Fractured specimens were examined with a stereo-microscope to determine the mode of failure. RESULTS:The bond strength(MPa) of OV,SE and(GB) in shallow lany-er of dentin was 44.96 ± 2.05,29.40 ± 1.77 and 16.38 ± 1.34(P<0.05),in deep layer 32.60 ± 1.58,22.79 ± 1.19 and 11.98 ± 0.91(P<0.05),respectively. The bond strength of the 3 self etching adhesives in the shallow layer was higher than that in the deep layer (P<0.05). No cohesive failure was observed in either superficial or deep dentin. Most of the failure was adhesive failure. CONCLUSION:The bond stength OV is the OV is the highest for dentine fol-lowed by SE and GB. The bonding strength of the 3 adhesives for shallow dentin were higher than that for deep dentin.