Bacterial reduction of mature Enterococcus faecalis biofilm by different irrigants and activation techniques using confocal laser scanning microscopy. An in vitro study

Abstract

Introduction: The aim of this study was to evaluate the effect of ultrasonic and sonic activation using three irrigants on mature Enterococcus faecalis biofilm. Materials and Methods: Seventy single-rooted premolars were prepared and sterilized. Mature E. faecalis biofilm was developed. Roots were randomly divided into three groups (n = 21) according to activation technique: ultrasonic, sonic, and positive control. Each group was further subdivided into three subgroups (n = 7) according to the irrigant used: 4% propolis, 2% chlorhexidine (CHX), and 2.5% sodium hypochlorite. Samples were cut and scanned using confocal laser scanning microscopy. The fluorescent images were analyzed using Zen imaging software. Data analysis was performed using one way analysis of variance and Tukey's honestly significant difference test for pairwise comparison. Statistical significance was set at 5%. Results: Both activated groups showed a statistically significant bacterial reduction (P ≤ 0.001). CHX showed the highest antibacterial effect. Conclusions: Irrigant activation is an essential step in reduction of bacterial counts. CHX has a potent antibacterial effect against mature E. faecalis biofilm.

Keywords

• bacterial biofilm
• confocal laser scanning microscopy
• irrigating solution
• sonic
• ultrasonic