Comparative evaluation of retreatment techniques by using different file systems from oval-shaped canals

Area of Science:

• Endodontics
• Dental Materials Science
• Restorative Dentistry

Background:

• Endodontic treatment failure necessitates material removal for successful outcomes.
• Complete obturating material removal is crucial for disinfection and healing.
• Nonsurgical retreatment aims to restore periradicular tissue health.

Purpose of the Study:

• To evaluate the efficacy of different retreatment systems in removing gutta-percha.
• To compare the time efficiency of various endodontic retreatment procedures.
• To determine the optimal retreatment strategy for different root canal thirds.

Main Methods:

• Seventy single-rooted mandibular premolars were used.
• Root canals were shaped, cleaned, and obturated.
• Seven groups tested different retreatment procedures, including hand files, rotary systems, and combinations with solvents and ultrasonics.

Main Results:

• All techniques left residual obturating material, with minimal amounts in Group 6 (MTwo® R with solvent and ultrasonics) and maximal in Group 5 (ProTaper Universal with solvent and ultrasonics).
• Group 2 (ProTaper Universal retreatment files) showed the minimum mean retreatment time, while Group 1 (Hand files) took the longest.
• MTwo® R with solvent and ultrasonics, R-Endo®, and R-Endo® with solvent and ultrasonics demonstrated effectiveness in gutta-percha removal from coronal, middle, and apical thirds, respectively.

Conclusions:

• Rotary file systems, particularly MTwo® R with solvent and ultrasonics, are effective for gutta-percha removal.
• Endodontic retreatment with rotary files facilitates disinfectant access, reducing microbial load.
• Successful retreatment promotes the healing of periradicular tissues.