Effectiveness of different obturation techniques in surpassing the ledge formed in simulated curved canals

Aim: To compare the effectiveness of different obturation techniques in surpassing the ledge formed in simulated curved root canals.
Methods: Eighty acrylic-resin blocks with curved canals were instrumented with Gates-Glidden drills to simulate a ledge formation. Then, a K-File #10 was used for trying to surpass the deviation, and the blocks that permitted surpassing were rejected. The remaining blocks were divided into 4 groups according to the obturation technique: lateral condensation, Tagger’s Hybrid technique, Thermafil and System B. The blocks had their images digitalized using a scanner before and after the obturation procedures. The images were analyzed with Image Tool 3.0 software. Statistical analysis was performed by one-way ANOVA at a significant level of 5%.
Results: The System B resulted in the highest obturated area (p<0.001). There were no significant differences between the Tagger’s Hybrid technique and Thermafil system regarding the effectiveness in surpassing ledge (p>0.05). The lateral condensation resulted in the worst ability in filling the ledge space (p<0.001).
Conclusions: Within the limitations of this study, it was possible to conclude that techniques using heat condensation or gutta-percha thermoplastification were more effective in surpassing the ledge formed in curved canals than the lateral condensation.

Keywords
endodontics, root canal therapy, root canal obturation, root canal filling materials