Comparison of various methods for removing double antibiotic paste from root canal walls during regenerative endodontic therapy

Abstract

Background:
Double antibiotic paste (DAP), commonly composed of metronidazole and ciprofloxacin, is used in regenerative endodontic therapy (RET) to disinfect the root canal. However, its removal prior to the final regenerative procedure is critical to avoid cytotoxic effects on stem cells. Various methods, including mechanical, chemical, and ultrasonic irrigation, have been employed to remove DAP from root canal walls. This study compares the efficacy of these techniques in ensuring the complete removal of DAP to optimize the regenerative outcomes.

Materials and Methods:

Eighty extracted human teeth with immature root apices were divided into four groups of 20 each. All teeth were subjected to DAP placement for 14 days. The methods for DAP removal included as Group 1: Manual irrigation with saline (Control Group), Group 2: Mechanical brushing using Endobrush, Group 3: Passive ultrasonic irrigation (PUI) with 17% EDTA and Group 4: Negative pressure irrigation (EndoVac) with 5.25% sodium hypochlorite. Post-procedure, the amount of residual DAP was evaluated using scanning electron microscopy (SEM), with arbitrary values assigned for quantitative assessment of paste removal from the canal walls.

Results:
The SEM analysis showed the following arbitrary DAP removal percentages as Group 1 (Saline irrigation): 35% DAP removal, Group 2 (Mechanical brushing): 60% DAP removal, Group 3 (PUI with EDTA): 85% DAP removal, Group 4 (EndoVac with NaOCl): 90% DAP removal. Group 4 showed the most effective DAP removal, followed closely by Group 3. Group 1 (saline irrigation) was the least effective, demonstrating significant residual DAP.

Conclusion:
Among the methods tested, EndoVac with sodium hypochlorite showed the highest efficacy in removing double antibiotic paste from the root canal walls. Passive ultrasonic irrigation with EDTA also showed promising results, while mechanical brushing and saline irrigation were comparatively less effective. Efficient removal of DAP is essential for successful regenerative endodontic therapy, particularly for minimizing cytotoxicity and improving tissue regeneration.