Apical extrusion of Enterococcus faecalis using three different rotary instrumentation techniques: an in vitro study

Area of Science:

• Endodontics
• Microbiology
• Dental Materials Science

Background:

• Apical extrusion of root canal bacteria during instrumentation can lead to post-operative infections.
• Understanding bacterial extrusion with different Nickel-Titanium (Ni-Ti) rotary systems is crucial for endodontic safety.

Purpose of the Study:

• To compare the apical extrusion of Enterococcus faecalis following root canal instrumentation using three distinct Ni-Ti rotary file systems.
• To evaluate the efficacy of Hyflex, GTX, and ProTaper systems in minimizing bacterial extrusion.

Main Methods:

• An in vitro study utilized 40 extracted mandibular premolars contaminated with Enterococcus faecalis.
• Teeth were instrumented with Hyflex, GTX, or ProTaper files, with a non-instrumented control group.
• Extruded bacteria were collected, incubated, and quantified using colony-forming units (CFUs).

Main Results:

• The GTX file system demonstrated the least amount of bacterial extrusion.
• Hyflex files showed a moderate level of bacterial extrusion.
• The ProTaper rotary system resulted in the maximum extrusion of Enterococcus faecalis.

Conclusions:

• GTX files appear to be the most effective in minimizing apical bacterial extrusion among the tested Ni-Ti rotary systems.
• Hyflex files offer a better alternative than ProTaper in reducing bacterial extrusion.
• Endodontic instrument selection can influence the risk of intraradicular bacterial dissemination.