Effectiveness of antibiotic medicaments against biofilm formation of Enterococcus faecalis and Porphyromonas gingivalis.

INTRODUCTION: In this study we compared the antibacterial effect of triple antibiotic paste (TAP), double antibiotic paste (DAP), and calcium hydroxide [Ca(OH)2] against Enterococcus faecalis and Porphyromonas gingivalis biofilm.

METHODS: The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and biofilm formation were measured by using microtiter plate methods. The 2 bacteria were treated with different dilutions of TAP, DAP, and Ca(OH)2 solutions. The turbidities of the bacterial cultures in the microtiter plate were measured by optical density at 490 nm by using a spectrophotometer. Data were analyzed by 2-way analysis of variance (α = 0.05).

RESULTS: For TAP, the MIC and MBIC values were 0.003 mg/mL for E. faecalis and 0.006 mg/mL for P. gingivalis. The MBC values for TAP were 0.3 mg/mL for both bacteria. The MIC and MBIC values for DAP were 0.001 mg/mL for E. faecalis and P. gingivalis. The MBC values for DAP were 0.14 mg/mL for both bacteria. Biofilm formation of the 2 bacteria was significantly decreased with TAP and DAP at all tested dilutions (P < .0001) compared with control groups; however, TAP and DAP biofilm formations were not significantly different from each other. Ca(OH)2 significantly decreased bacterial biofilm formation compared with the control, but it was significantly less than TAP and DAP (P < .05).

CONCLUSIONS: Both TAP and DAP were more effective than Ca(OH)2 against E. faecalis and P. gingivalis. DAP can be considered an effective and comparable antibacterial substitute for TAP.