The Effect of Adding Different Antibiotics on the Resistance against Bacterial Leakage of AH 26 Sealer

Aim: Most endodontic sealers show antimicrobial activity before setting, but most of them also lose this ability after setting. Addition of an antibiotic may affect the properties of sealers such as sealing ability, setting time, and so on. The aim of this study was to assess whether the addition of antibiotics (amoxicillin, doxycycline, and clindamycin) improves the sealing ability of AH 26 sealer. Materials and Methods: Seventy extracted human mandibular premolars were used. After cleaning and shaping the canals, the teeth were divided into six groups: group 1: gutta-percha and AH 26 sealer, group 2: gutta-percha and AH 26 sealer+doxycycline, group 3: gutta-percha and AH 26 sealer+amoxicillin, group 4: gutta-percha and AH 26 sealer+clindamycin, group 5: gutta-percha without sealer (positive control), and group 6: gutta-percha and AH 26 sealer (the root surfacewere covered with nail varnish) (negative control). A microbial leakage model was used to assess the sealing ability. Results: Group 2 had the greatest resistance against bacterial leakage. Furthermore, combining AH 26 sealer with amoxicillin and clindamycin increased mean leakage time compared to AH 26 sealer solely. However, the differences between groups 1 and 3 as well as between groups 1 and 4 were not statistically significant. Conclusion: Incorporating antibiotics especially doxycycline into AH 26 sealer increases its resistance against bacterial leakage.