Effect of eugenol-containing sealer and post diameter on the retention of fiber reinforced composite posts

Background: Fiber reinforced composite (FRC) posts are cemented with resin cements. It is reported that using resin cements in canals sealed with eugenol-containing sealers reduces the post retention. However, there is controversy on the subject.

Aims: The aim was to investigate the influence of eugenol-containing sealers and the amount of dentin removal from root canal with different post diameters on retention of FRC posts.

Settings and design: It was an in vitro study

Materials and methods: The roots of sixty teeth were cut with 14 mm distance from the apex and were instrumented to the working-length of 13 mm. The teeth were randomly distributed into 2 groups (n = 30). Following storage in normal saline for 7 days, the samples in both the groups were further divided into 3 subgroups (n = 10). Canals in the experimental subgroups (I, II, III) were obturated by gutta-percha and eugenol-containing sealer; and in the control subgroups (IV, V, VI) without any sealer. After storage in normal saline for 7 days, the post space was prepared by #3, #2, and #1 drills of DT Light-Post system. Post was cemented with Panavia-F2.0 resin-cement. A composite core was built for each sample. All samples were thermo cycled for 1000 cycles. The samples were tested for post retention with a mechanical testing machine.

Statistical analysis: Data were analyzed by two-way ANOVA and Tukey-HSD test.

Results: There was not a significant difference in retention between FRC posts #1 and #2 (P > 0.05). Post #3 was more retentive than posts #1and #2 (P < 0.05). ZOE sealer significantly reduced the retention of posts (P = 0.024), however, increasing post-space diameter significantly increased post retention in canals coated with ZOE sealer (P = 0.002).

Conclusions: Eugenol-containing sealer reduced the retention of FRC posts cemented with resin cement. Removing more dentin from root-canals treated with eugenol-containing sealer for placing larger diameter posts caused an increase in post retention.