Endodontic fit of two different fibre post systems: single versus double taper

Aim To evaluate the fit against root canal walls obtained with a single-taper post system, placed without further canal enlargement, and a double-taper post system requiring traditional post space preparation with burs. Methodology Twenty straight single-rooted teeth were cut to obtain 14 mm-long roots. Canals were shaped with Mtwo rotary files up to size 40, 04 taper and filled with the continuous wave of condensation technique, leaving an unfilled coronal space of 9 mm. Ten roots were randomly assigned to group 1 (G1) and received a SurgiPost Multiconical single-tapered post, which had previously undergone standardised trimming. In the remaining roots (G2), the post space was prepared with the bur of the DT Light-post system to place a double-taper post of corresponding size. The posts were luted with RelyX self-adhesive cement. Cement thickness was measured on sectioned specimens at the scanning electron microscope (120 readings per post third). Parametric statistical tests were used to compare the cement thickness between the two groups and among post thirds (a = 0.05). Results At the coronal level, cement thickness was minimum and similar in the two groups. The effects of drilling were visible on the canal walls on the apical third of the post in G1, which was characterized by even cement distribution irrespective of the post third. The cement thickness was limited also in G2, but slightly increased at the post tip (p < 0.05). Conclusions The post systems achieved satisfactory fit in straight single-rooted teeth in the coronal and middle post thirds. At the tip of the post, the post space preparation with drills allowed for excellent fit but required further removal of dentine, while single-taper posts provided an inferior fit at this level due to the standardised methodology needed in the research setting.