Assessing the Iatrogenic Contribution to Contamination During Root Canal Treatment

Shatha Zahran; Francesco Mannocci; Garrit Koller

doi:10.1016/j.joen.2022.01.007

Assessing the Iatrogenic Contribution to Contamination During Root Canal Treatment

J Endod. 2022 Apr;48(4):479-486. doi: 10.1016/j.joen.2022.01.007. Epub 2022 Jan 23.

Authors

Shatha Zahran¹, Francesco Mannocci², Garrit Koller³

Affiliations

¹ Department of Endodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Endodontics, Centre for Oral, Clinical and Translational Sciences, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK. Electronic address: shatha.zahran@kcl.ac.uk.
² Department of Endodontics, Centre for Oral, Clinical and Translational Sciences, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK.
³ Department of Endodontics, Centre for Oral, Clinical and Translational Sciences, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; Centre for Host Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; London Centre for Nanotechnology, London, UK.

PMID: 35081439
DOI: 10.1016/j.joen.2022.01.007

Abstract

Introduction: Asepsis in endodontics aims to control all potential sources of infection. Inadvertent introduction of bacteria into the root canal system may occur when the aseptic chain is breached during treatment. Therefore, measures are taken to prevent such microbial access and establish an aseptic environment. This study aimed to assess potential bacterial contamination and the potential risk of iatrogenic introduction from 7 sites comprising surfaces, instruments, and files acquired during the treatment of 30 vital, pulpitic teeth.

Methods: Bacterial samples were collected from access burs, files, endodontic rulers, rubber dam surfaces, gloves, and instruments. Genomic DNA was extracted and quantified by quantitative polymerase chain reaction. Bacterial types were determined using next-generation sequencing.

Results: High frequencies of contamination and microbial numbers were encountered in all sample types examined.Thirty-eight percent of the initial files introduced into the root canal had significant levels of bacteria at the point of obturation, including endodontic pathogens. Around half of the rubber dam surfaces were contaminated with substantial bacterial loads at the time of obturation, and bacteria were also detected in 20%-30% of gloves, instruments, and rulers before obturation. Next-generation sequencing revealed the predominant oral or endodontic origin of these contaminants, with the following genera identified: Streptococcus, Rothia, Granulicatella, Cutibacterium, Corynebacterium, Peptostreptococcus, and Fusobacterium. Together, these findings highlight the potential risk of reintroducing endodontically relevant bacteria during treatment.

Conclusions: Gloves, rubber dams, instruments, and files acquire bacterial contamination during treatment at high frequencies and loads. This highlights the potential risk of iatrogenic contamination at the clinically vulnerable point of canal obturation. Measures to address these may improve clinical outcomes.

Keywords: Asepsis; contamination; next-generation sequencing; quantitative polymerase chain reaction; root canal treatment.

MeSH terms

Dental Pulp Cavity* / microbiology
Humans
Iatrogenic Disease
Root Canal Obturation
Root Canal Preparation
Root Canal Therapy*
Rubber Dams