Translucent fiber post cementation using a light-curing adhesive/composite system: SEM analysis and pull-out test

The performance of both light-curing and dual-cured adhesive/luting systems (as control), when used in combination with translucent fibre posts, was evaluated by means of pull-out test and scanning electron microscopy (SEM ) observation.

Forty root canal treated teeth were randomly divided into two groups of 20 specimens each. Group 1 light-curing system: Excite and Tetric Flow; Group 2 dual cured system: All Bond 2+RelyX ARC. Translucent, double taper fibre posts were used (2.1/1.4mm diameter). The teeth were stored in NaCl 0.9% solution at 37 degrees C. A week later, the pull-out test was carried out on all specimens. Ten tested specimens for each group and their corresponding posts were processed for SEM observation. Statistical analysis was performed applying one-way analysis of variance (ANOVA) followed by T-test as post-hoc comparison at a significance level set at p<0.05.

There is no statistically significant difference (p>0.05) between the light-curing system group (275.2+/-58.9N) and the dual cured one (301.4+/-40.1N). SEM observations confirm a good bond between the dentine and the post whatever the curing method employed.

Dual curing of the All Bond 2+RelyX ARC system seems to be the most appropriate method since it allows to cure even those areas which would not be otherwise reached by light. On the other hand, in apical areas, the incomplete curing of the Excite+Tetric Flow system could improve the post adaptation and allow the achievement of both an improved apical seal and a more even distribution of the stress along the canal walls.