Comparative Evaluation of the Antimicrobial Efficacy of Endodontic Sealers Against Staphylococcus aureus and Streptococcus mutans: An In Vitro Study.

INTRODUCTION

Endodontic therapy aims to eliminate microbial infections from the root canal system and prevent reinfection, thus ensuring periapical tissue healing. Persistent bacterial contamination, particularly from Staphylococcus aureus and Streptococcus mutans, is a major cause of endodontic treatment failure. Owing to the complexity of the root canal anatomy, conventional mechanical and chemical disinfection methods may be insufficient to eliminate bacteria. Endodontic sealers with antimicrobial properties play a crucial role in enhancing disinfection and preventing bacterial re-colonization. This study aimed to evaluate and compare the antimicrobial efficacy of three commonly used endodontic sealers, AH Plus (Dentsply Maillefer, Ballaigues, Switzerland), Zinc Oxide Eugenol (ZOE; Pyrax Cavibond, Roorkee, India), and Tubli Seal (SybronEndo, Glendora, CA, USA), against Staphylococcus aureus and Streptococcus mutans using the agar diffusion method.

MATERIALS AND

METHODS

This in vitro study was conducted at the Department of Conservative Dentistry and Endodontics between May 2024 and October 2024. The antimicrobial properties of three endodontic sealers - AH Plus, ZOE sealer, and Tubli Seal - were tested against Staphylococcus aureus ATCC 25923 and Streptococcus mutans ATCC 700610. The bacterial suspensions were standardized to 1.5 × 10⁸ colony-forming units (CFU)/ml. Agar wells (6 mm diameter, 5 mm depth) were filled with freshly mixed sealers and inhibition zones were measured using a digital caliper at 24 hours and seven days. Statistical analysis was performed to compare the antibacterial efficacy of sealers over time.

RESULTS

At 24 hours, AH Plus exhibited the highest antimicrobial activity against both bacterial species (p < 0.05), followed by the Tubli Seal and ZOE. By seven days, the ZOE sealer demonstrated the most potent antibacterial effect, surpassing AH Plus and Tubli Seal (p < 0.05). Both AH Plus and Tubli Seal exhibited a decline in the antibacterial activity over time. All the sealers were more effective against Streptococcus mutans.

CONCLUSION

Endodontic sealers exhibit time-dependent antibacterial properties. AH Plus is the most effective sealer in the early stages of treatment, providing strong initial bacterial suppression, whereas ZOE sealer demonstrated sustained antimicrobial activity over time. The Tubli Seal showed moderate efficacy. These findings emphasize the importance of sealer selection based on clinical scenarios.