Evaluation of the apical sealing ability of remaining gutta-percha after fiber post placement

Abstract

Aim: The aim of this study is to evaluate the ability of the remaining gutta-percha (GP) in the apical third of root canals after fiber post placement. Materials and methods: Thirty single root canals extracted were sectioned to 18 mm and divided into three groups. All the root canals were shaped with ProTaper Next (X3 file) and filled with GP and resin-based sealer at three different lengths (4, 5, and 7 mm) from the root apex. The fiber post placement was constructed immediately. The roots were immersed in methylene blue dye for 14 days and transversely sectioned in disks of 1 mm thick from the apex to the post. The evaluation of the dye penetration was done using a stereomicroscope. One-way analysis of variance (ANOVA) and multiple comparisons of Scheffe’s tests were used to test the length of dye penetration. Chi-squared test was used to test dye penetration scale (p < 0.05). Results: In the group 3 where the left (or remaining) GP was 7 mm, the dye penetration scale was lower compared with the other groups (p < 0.05). There was less dye penetration at 6 mm from the apex, and there was no penetration at 7 mm from the apex. The dye penetration scale was generally decreased from the 1 mm level disk to the 4 mm level disk in all the groups. Conclusion: A 7 mm length of remnant GP is necessary to obtain an improved apical seal in the cases where a post retention restoration is required in an endodontic treated tooth. Clinical significance: To maintain the integrity of the apical sealing, it is necessary to leave 7 mm of GP in the apical third of the root canal. The “standard gold” of 5 mm of the apical seal with GP cannot prevent apical leakage.