Comparative Retreatment Efficacy of Two Multi-File Systems with Different Access Cavity Designs: A Micro-Computed...

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Root canal retreatment aims to remove obturation materials.
• Access cavity design and instrumentation systems may influence retreatment efficiency.

Purpose of the Study:

• To evaluate the efficiency of two multi-file systems in removing obturation materials.
• To compare the effects of conservative (CAC) and traditional (TAC) access cavities on retreatment outcomes.
• To utilize micro-computed tomography (micro-CT) for quantitative analysis.

Main Methods:

• 80 mandibular premolars were prepared and obturated.
• Samples were divided into CAC and TAC groups, then further into eight subgroups based on retreatment systems (ProTaper Next and ProTaper Ultimate).
• Micro-CT scans quantified remaining obturation material before and after retreatment.

Main Results:

• Access cavity design (p=0.500), ProTaper system (p=0.138), and their interaction (p=0.513) had no significant effect on remaining material.
• Group 3 (TAC and PTN) had the highest percentage of remaining material (29.53%).
• Group 6 (CAC and PTR + PTUL) showed a lower percentage of remaining material.

Conclusions:

• Complete removal of obturation materials was not achieved by any tested retreatment procedure.
• Access cavity design and multi-file systems showed no significant impact on the amount of residual root canal filling material.