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Effect of Additional Apical Preparation on Retreatment of Curved Root Canals Filled with Different Sealers
Karina I M C Tavares1, Jader C Pinto1, Airton O Santos-Junior1
1Department of Restorative Dentistry, School of Dentistry, São Paulo State University, Araraquara, São Paulo, Brazil.
Objective:
This study assessed the influence of additional apical preparation on material removal during retreatment of curved root canals filled with different sealers.
Materials And Methods:
Twelve mesial roots of mandibular molars with two separate canals and curvature between 25 and 35 degrees were selected. The working length was established 1-mm short of the apical foramen, and all the root canals were prepared using ProDesign R (PDR) 25/0.06. After preparation, the root canals were divided in two groups (n = 12) and filled by continuous wave condensation technique with NeoMTA Plus or AH Plus. All the root canals were retreated using rotary ProDesign Logic RT 25/0.08, reciprocating PDR 25/0.06 and apical preparation with PDR 35/0.05. Additional apical preparation was performed with ProDesign Logic (PDL) 50/0.01. The samples were scanned using a Skycan 1176 micro-computed tomography (micro-CT), voxel size 8.74 µm, before and after the retreatment procedures. Percentages of remaining filling material were evaluated.
Statistical Analysis:
The data were submitted to paired and unpaired t-tests (α = 0.05).
Results:
Percentage of remaining filling material was similar between the root canals filled with NeoMTA Plus or AH Plus sealer after retreatment using PDR 35/0.05, and after additional apical preparation using PDL 50/0.01 (p > 0.05). However, PDL 50/0.01 significantly decreased the percentage of remaining filling material in the apical third after the additional apical preparation for both sealers (p < 0.05).
Conclusion:
NeoMTA Plus or AH Plus did not influence the retreatment of curved root canals. ProDesign Logic 50/0.01 promoted greater filling material removal in the apical third.
