Avaliação da extrusão bacteriana apical após instrumentação mecanizada com sistemas reciprocantes de instrumento único comparados a um sistema rotatório multi-instrumento

Abstract

The aim of this work was to evaluate ex vivo the apical bacterial extrusion of reciprocating single-file systems (Wave One® and Reciproc®) compared to a multi-file rotary system (BioRaCe®). This was tested in the current study using extracted, single-rooted teeth with oval canals (n = 45) with similar anatomy. Endodontic access cavities were prepared and root canals were contaminated with an Enterococcus faecalis suspension and incubated for thirty days to promote bacterial biofilm growth. The contaminated teeth were divided into three groups with 15 specimens each (RE - Reciproc®, WO- Wave One® and BR - BioRaCe®). Positive and negative bacterial growth control groups were done. Bacterial extruded from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbiological samples were taken from the vials and incubated in BHI agar medium during 24h. Bacterial growth was counted and the results were given by colony-forming units (CFU). These data were analyzed by Wilcoxon matched-pairs signed rank test and Kruskal Wallis H-test. After data analysis, no significant difference was found in the number of CFU between the two reciprocating systems (p > 0.05). Conventional multi-file rotary system group showed significantly higher CFU than both of the other two reciprocating groups (p<0.05). Based on the results evaluation and within the limitation of this study, it was possible to conclude that all tested instrumentation systems extruded bacteria beyond the apex. However, both reciprocation single-file systems apically extruded fewer bacteria than the conventional multi-file rotary system.