Comparison of apical extrusion of intracanal bacteria by various glide-path establishing systems: an in vitro study

OBJECTIVES: This study compared the amount of apically extruded bacteria during the glide-path preparation by using multi-file and single-file glide-path establishing nickel-titanium (NiTi) rotary systems. MATERIALS AND METHODS: Sixty mandibular first molar teeth were used to prepare the test apparatus. They were decoronated, blocked into glass vials, sterilized in ethylene oxide gas, infected with a pure culture of Enterococcus faecalis, randomly assigned to 5 experimental groups, and then prepared using manual stainless-steel files (group KF) and glide-path establishing NiTi rotary files (group PF with PathFiles, group GF with G-Files, group PG with ProGlider, and group OG with One G). At the end of canal preparation, 0.01 mL NaCl solution was taken from the experimental vials. The suspension was plated on brain heart infusion agar and colonies of bacteria were counted, and the results were given as number of colony-forming units (CFU). RESULTS: The manual instrumentation technique tested in group KF extruded the highest number of bacteria compared to the other 4 groups (p < 0.05). The 4 groups using rotary glide-path establishing instruments extruded similar amounts of bacteria. CONCLUSIONS: All glide-path establishment instrument systems tested caused a measurable apical extrusion of bacteria. The manual glide-path preparation showed the highest number of bacteria extruded compared to the other NiTi glide-path establishing instruments.

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

Aims: To compare the apical extrusion of Enterococcus faecalis after instrumentation with three different Ni-Ti rotary instruments- An in vitro study. Settings and Design: In vitro study Methods and Material: Forty freshly extracted mandibular premolars were mounted in bacteria collection apparatus and root canals were contaminated with a suspension of Enterococcus faecalis. The contaminated teeth were divided into 4 groups of 10 teeth each according to rotary system used for instrumentation: Group1: Hyflex files, Group 2: GTX files, Group 3: Protaper files and Group 4: control group (no instrumentation). Bacteria extruded after preparations were collected into vials and microbiological samples were incubated in BHI broth for 24 hrs. The colony forming units were determined for each sample. Statistical Analysis Used: Statistical analysis was done using one way ANOVA followed by post hoc independent “t” test. Results: GTX files extruded least amount of bacteria followed by Hyflex files. Maximum extrusion of E. faecalis was seen in rotary Protaper group. Conclusion: Least amount of extrusion was seen with GTX files followed by Hyflex files and then rotary Protaper system.