Sealing ability of three fiber post systems

Objectives: To study the sealing ability of 3 fiber post systems using ammoniacal silver nitrate. Methods: Thirty-six single-rooted teeth were endodontically treated and randomly assigned to two new fiber post systems and a control group: EV - everStick-POST + ParaCem Universal DC resin cement; RX - RelyX Fiber Post + RelyX Unicem resin cement; PP - ParaPost Fiber Lux + ParaCem Universal DC resin cement (control group). The roots were isolated with nail polish except for a 1.0 mm rim around the post, and immersed in 50wt% ammoniacal silver nitrate for 24 h followed by 8 h in photodeveloping solution. The roots were sectioned in 1 mm-thick disks and processed for backscatterered FESEM. For each tooth, the depth of silver infiltration was divided in ranks from 0 to 8. Additionally, leakage was measured for each disk as the percentage of silver penetration around the adhesive interface. Data were analyzed with Kruskal-Wallis non-parametric test (P<0.05). Results: No leakage occurred at the post-cement interface. For depth of silver penetration, RX resulted in the lowest degree of nanoleakage, but not statistically different from that of EV (P<0.148).RX resulted in lower degree of leakage than PP at P<0.023. EV resulted is statistically similar depth of penetration than PP at P=0.492. The mean percentage of silver infiltration at the dentin-resin cement interface was statistically similar for all groups (P>0.05). However, EV resulted in the greater number of disks with nanoleakage (23 out of 96), followed by PP (21 out of 96) and RX (14 out of 96). Conclusion: The use of the new IPN technology in EV did not improve the root wall sealing ability compared with the control group. RX, which uses a new simplified self-adhesive protocol, resulted in a tighter seal to root dentin than the control.