Push-out bond strengths of fiber-reinforced composite posts with various resin cements according to the root level.
OBJECTIVE
The aim of this study was to determine whether the push-out bond strengths between the radicular dentin and fiber reinforced-composite (FRC) posts with various resin cements decreased or not, according to the coronal, middle or apical level of the root.


METHODS
FRC POSTS WERE CEMENTED WITH ONE OF FIVE RESIN CEMENT GROUPS (RELYX UNICEM: Uni, Contax with activator & LuxaCore-Dual: LuA, Contax & LuxaCore-Dual: Lu, Panavia F 2.0: PA, Super-Bond C&B: SB) into extracted human mandibular premolars. The roots were sliced into discs at the coronal, middle and apical levels. Push-out bond strength tests were performed with a universal testing machine at a crosshead speed of 0.5 mm/min, and the failure aspect was analyzed.


RESULTS
There were no significant differences (P>.05) in the bond strengths of the different resin cements at the coronal level, but there were significant differences in the bond strengths at the middle and apical levels (P<.05). Only the Uni and LuA cements did not show any significant decrease in their bond strengths at all the root levels (P>.05); all other groups had a significant decrease in bond strength at the middle or apical level (P<.05). The failure aspect was dominantly cohesive at the coronal level of all resin cements (P<.05), whereas it was dominantly adhesive at the apical level.


CONCLUSIONS
All resin cement groups showed decreases in bond strengths at the middle or apical level except LuA and Uni.
Department of Conservative Dentistry, Dental Science Research Institute, School of Dentistry, Chonnam National University, Gwangju, Republic of Korea.
Hoon-Sang
HS
Chang
Young-Sin
YS
Noh
Yoon
Y
Lee
Kyung-San
KS
Min
Ji-Myung
JM
Bae
Bond strength; Fiber reinforced-composite post; Resin cements; Root level