Bacterial Reduction after Gutta-Percha Removal with Single vs. Multiple Instrument Systems

Area of Science:

• Endodontics
• Microbiology

Background:

• Root canal infections often involve Enterococcus faecalis.
• Gutta-percha removal is a critical step in retreatment.
• Evaluating endodontic instrument efficacy is crucial for infection control.

Purpose of the Study:

• To compare the efficacy of a reciprocating single-instrument system (Reciproc-REC) versus combined continuously rotating multiple-instrument systems (D-Race/BioRace) in reducing E. faecalis after gutta-percha removal.

Main Methods:

• Extracted human incisors were contaminated with E. faecalis.
• Samples were obturated and divided into REC and DR/BR groups for gutta-percha removal.
• Bacterial quantification was performed before and after gutta-percha removal using paper points and culture.
• Time for gutta-percha removal was recorded.

Main Results:

• The D-Race/BioRace group showed a significantly higher bacterial reduction (84.2%) compared to the Reciproc-REC group (72.3%).
• Gutta-percha removal time was significantly shorter with the Reciproc-REC system (74.00 sec) than the DR/BR system (107.53 sec).

Conclusions:

• Combined continuously rotating instruments are more effective for bacterial reduction post-gutta-percha removal than single reciprocating instruments.
• Neither system achieved complete elimination of root canal infection.
• Additional disinfection techniques may be necessary for complete root canal sterilization.