Baccor, in vitro formation of biofilm in broken endodontic files in radicular canals

Fabiano Luiz Heggendorn,Lúcio Souza Gonçalves,Hesham Mohammed Al-Sharani,Márcia Teresa Soares Lutterbach,Walter Barreiro Cravo Junior,Viviane De Oliveira Freitas Lione

doi:10.33448/rsd-v11i1.23849

Abstract

The aim of this study to evaluate the biofilm formation of sulfate-reducing bacteria from two microbial species, Desulfovibrio desulfuricans (oral and environmental strain) and Desulfovibrio fairfieldensis, in root canals with fractured endodontic files in vitro and the biocorrosive changes that these strains are capable of promoting on the metal surface of endodontic files. Fourteen teeth were included with fractured # 90 Kerr files and inoculants of Desulfovibrio desulfuricans strains and Desulfovibrio fairfieldensis in a modified Postgate E culture medium. The inoculated teeth were evaluated at 28, 41, 51 and 477 days. The biofilm was evaluated through scanning electron microscopy (SEM) and confocal laser scanning microscope with the fluorophore the Live / Dead® kit. For the 477 day, chemical pickling followed, with subsequent evaluation of the metallic surface of endodontic files in the SEM. In the biofilm analyzes of 28, 51 and 477 days, a mixed biofilm was observed, with a predominance of living cells and areas of corrosion along the entire metallic surface of the file for the last time, contrasting the metallic surface of the control groups. The SRB showed cellular activity both on the metal surface of the file and on the dentin surface of the root canal at the deepest levels of the root canal, apical and medium, promoting biocorrosion along the metal surface of endodontic files.

Highlights

Different techniques are used in the removal of fractured endodontic instruments in root canals, such as hemostatic forceps for apprehending the fragment, overtaking the fragment for subsequent traction with Kerr files, ultrasound and even the use of cyanoacrylate for adhesion of the fragment with another instrument. in an attempt to achieve success in removing the lime fragment (Gaffney, et al, 1981, Coutinho, et al, 1998, Nehme, 1999, De Oliveira, 2003, Suter, et al, 2005)
The present study aimed To evaluate the biofilm formation of sulfate-reducing bacteria from two microbial species, Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis, in root canals with fractured endodontic files in vitro and the biocorrosive changes that these strains are capable of promoting on the metal surface of endodontic files through the use of fluorescence microscopy and scanning electron microscopy techniques
A Postgate E culture medium was added to the microtube in the outer apical region of the root, plus Agar-agar, 15g / l., in order to fix the tooth inside the microtube after solidification of the medium and indicate bacterial confinement within the root canal, since, in case of contamination of external regions of the root, the culture medium will indicate this contamination through the change of colour and formation of iron sulfide (Figure 1)

Summary

Introduction

Different techniques are used in the removal of fractured endodontic instruments in root canals, such as hemostatic forceps for apprehending the fragment, overtaking the fragment for subsequent traction with Kerr files, ultrasound and even the use of cyanoacrylate for adhesion of the fragment with another instrument. in an attempt to achieve success in removing the lime fragment (Gaffney, et al, 1981, Coutinho, et al, 1998, Nehme, 1999, De Oliveira, 2003, Suter, et al, 2005). Different techniques are used in the removal of fractured endodontic instruments in root canals, such as hemostatic forceps for apprehending the fragment, overtaking the fragment for subsequent traction with Kerr files, ultrasound and even the use of cyanoacrylate for adhesion of the fragment with another instrument. In order to assist in the removal of fractured instruments from the inside of the root canal, BACCOR was developed. A fundamental step in this process is the capacity of biofilm formation by microorganisms, where, through their metabolism, they induce and maintain the oxygen concentration gradient, accelerating the corrosion process through the reduction of oxygen and the release of their metabolic products (Videla, 2003, Larry & Hamilton, 2007)

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Results

Discussion

Conclusion