Evaluation of Residual Antibacterial Effect of Human Radicular Dentin Treated with Triple and Double Antibiotic Pastes

Introduction: The aim of this study was to investigate the residual antibacterial effect of human radicular dentin treated with various concentrations of triple antibiotic paste and double antibiotic paste (DAP). Methods: Sterilized dentin specimens were randomly assigned to 6 treatment groups and a no-treatment control group (n = 45 per group). For treatment groups, specimens were treated with either TAP or DAP at various concentrations (1000, 1, or 0.5 mg/mL) for 2 weeks. Then, each specimen was irrigated with 5 mL saline and incubated in phosphate-buffered solutions for 3, 7, 14, or 30 days. After that, Enterococcus faecalis was cultured on the specimens for 3 days. Each specimen was then transferred to a tube containing 200 mu L saline, sonicated, and vortexed to detach the bacterial biofilm. The detached biofilm was spiral plated, and the number of colony-forming units was determined using an automated counting machine. Results: Dentin specimens treated with 1000 mg/mL TAP or DAP had a significant residual antibacterial effect up to 14 days and 30 days, respectively. No significant difference was observed between 1000 and 1 mg/mL. TAP and DAP at all time points. Dentin treated with all concentrations of DAP has a significantly longer residual antibacterial effect compared with dentin treated with TAP at the same concentrations. Conclusions: Radicular dentin treated with TAP and DAP showed a significant residual antibacterial effect compared with untreated dentin. All concentrations of DAP showed a significantly longer residual antibacterial effect compared with the same concentrations of TAP.