The effect of environmental pressure and resin cements on the push-out bond strength of a quartz fiber post to teeth root canals

Aim: To evaluate the effect of environmental pressure changes on the bond strength between a fiber post and one of three resin cements using different mixing methods and modes of application. Methodology: Sixty single-canal human teeth were divided into three groups (n=20) and endodontically treated. Post spaces were prepared, and a quartz fiber post was secured with either a self-adhesive machine-mixed cement (RelyX Unicem, Aplicap), a self-adhesive hand-mixed cement (RelyX Unicem), or a self-etching dual-cured resin cement (Panavia F2). Half of each group was subjected to 24 pressure cycles from 0 to 5 atmospheres. The mean push-out bond strength of the posts was calculated and statistically analyzed using ANOVA and Tukey tests (alpha = 0.05). Results: Regardless of the pressure, Unicem Aplicap achieved the highest bond strength (P<0.05). The bond strengths of all groups were significantly lower after they were subjected to the pressure cycles (P < 0.003), and they were lower in the apical regions. Conclusion: Bond strengths between the fiber post and root canal can be affected by environmental pressure while the type of resin cements, their mixing methods and modes of application incorporated lower porosity, achieving higher bond strength.