The Radiopacity and Antimicrobial Properties of Different Radiopaque Double Antibiotic Pastes Used in Regenerative Endodontics.

Introduction: We evaluated the radiopacity and antibacterial properties of various concentrations of double antibiotic paste (DAP) containing barium sulfate (BaSO ₄ ) or zirconium oxide (ZrO ₂ ) radiopaque agents.
Methods: The radiopacity of 1, 10, and 25 mg/mL DAP containing 30% (w/v) BaSO ₄ or ZrO ₂ , DAP-free radiopaque pastes, and commercially available radiopaque calcium hydroxide (Ca[OH] ₂ ) were evaluated according to ISO 6876/2001 with slight modifications (n = 6 per group). Dentin samples (n = 70) infected anaerobically for 3 weeks with bacterial biofilms obtained from a root canal of an immature tooth with pulpal necrosis were treated with similar experimental pastes or received no treatment (n = 7). After 1 week, the pastes were rinsed off, and biofilm disruption assays were conducted. To show the residual antibacterial effects, sterile dentin samples (n = 70) were pretreated for 1 week with the same pastes (n = 7). The pastes were rinsed off, and the samples were immersed in phosphate-buffered saline for 24 hours and infected anaerobically with the same bacterial biofilm mentioned earlier for 3 weeks before conducting biofilm disruption assays. Sterile dentin blocks were used in both antibacterial analyses as negative control groups (n = 7). Wilcoxon rank sum tests were used for statistical analyses.
Results: No tested concentrations of BaSO ₄ DAP or ZrO ₂ DAP showed significant differences from Ca(OH) ₂ in radiopacity. However, all tested concentrations of BaSO ₄ DAP, ZrO ₂ DAP, and Ca(OH) ₂ exhibited significant direct antibacterial effects. ZrO ₂ DAP at 1 mg/mL and Ca(OH) ₂ did not show significant residual antibacterial effects.
Conclusions: BaSO ₄ DAP at 1 mg/mL provided significantly superior residual antibacterial effects and comparable radiopacity with the commercially available Ca(OH) ₂ .
(Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)