Influence of two obturation techniques with and without immediate post-space preparation on the apical sealing ability of two endodontic sealers: An in vitro study

Abstract Objectives: This study aimed to evaluate the impact of two obturation techniques, with and without immediate thermal post-space preparation, on the apical seal of two endodontic sealers. Methods: The root canals of 140 extracted maxillary central incisors were prepared after cutting their crown, and 120 were divided into two groups (n=60): Group I, without post-space preparation, and Group II, with immediate thermal post-space preparation. Each group was further divided into four subgroups (n=15) according to materials and techniques of obturation: Subgroup A (AH Plus / single-cone), Subgroup B (AH Plus / lateral condensation), Subgroup C (GuttaFlow Bioseal / single-cone), and Subgroup D (GuttaFlow Bioseal / lateral condensation). The remaining 20 roots served as control groups (n=10) and for the preparation of blank solutions (n=10). The apical seal was assessed using the dye extraction method. Data were analyzed using one-way analysis of variance (ANOVA) and independent t tests. Results: Apical leakage values for GuttaFlow Bioseal and AH Plus were significantly influenced by the obturation techniques and immediate post-space preparation (p<0.05). Without post-space preparation, GuttaFlow Bioseal / single-cone demonstrated the lowest apical leakage (0.149±0.006 μl). With post-space preparation, AH Plus/lateral condensation exhibited the lowest leakage (0.152±0.035 μl). Apical leakage increased significantly with post-space preparation (P<0.05) when the single cone technique was used with both sealers and when the lateral condensation technique was used with GuttaFlow Bioseal, while the apical seal was not affected when the lateral condensation technique was used with AH Plus (p=0.318). Conclusion: The apical seal of both sealers was significantly influenced by the obturation technique and the presence of immediate post-space preparation. GuttaFlow Bioseal demonstrated the best apical seal when used with the single-cone technique and without immediate post-space preparation. On the contrary, AH Plus achieved optimal apical sealing when combined with the lateral condensation technique and immediate post-space preparation.