Microbial flora of root canal–treated teeth associated with asymptomatic periapical radiolucent lesions

Abstract

This study aimed to investigate the composition of microflora in endodontically treated teeth associated with asymptomatic periapical lesions in southern Chinese patients. Twenty-four teeth which had received nonsurgical root canal treatment more than 4 years previously, and which presents an acceptable coronal restoration with a periapical radiolucent area, were re-treated nonsurgically. Bacteriological samples were obtained after removal of the old root canal filling. The samples were inoculated on enriched trypticase soy agar and four selective media for incubation at 37 degrees C in both a carbon dioxide-enriched atmosphere and anaerobically. Eighteen teeth that had received gutta-percha root canal fillings were grouped for analysis, 12 (66.7%) of which contained cultivable microorganisms. The total colony forming units per ml of transport medium ranged from 0 to 2.3 x 10(5). The number of bacterial genera recovered ranged between 0 and 6, with facultative gram-positive cocci being the most prevalent group of bacteria isolated. Facultative anaerobic bacteria were present in all, whereas strict anaerobic bacteria were found in 3 out of the 12 teeth with positive growth. The size of the periapical rarefaction did not show any relationship with the quantity of microorganisms recovered. Coagulase-negative staphylococci, streptococci and Pseudomonas aeruginosa were most frequently isolated in this group of patients. The possible origin of these organisms is discussed.

Endodontic retreatment: clinical comparison of reciprocating systems versus rotary system in disinfecting root canals

“…In consonance, at the baseline samples, the present study revealed the presence of cultivable bacteria in 100 % of the samples from endodontically treated teeth. The initial number of viable bacteria in post-treatment apical periodontitis ranged from 10 2 to 10 5 CFU/mL, which is comparable to previous investigations [7,26,27].…”

“…Controversies, exists on the use of solvent during endodontic retreatment [16,17,26]. Although solvents such as chloroform have been use to facilitate the process, their side-effects-i.e., cytotoxic potential and potential for forming a residual film of softened gutta-percha on the dentin walls-can overcome their benefits [17,26].…”

A big role for the very small—understanding the endodontic microbial flora

“…The prevalence of enterococci has been a conspicuous finding in all studies that have investigated the flora in root-filled teeth, [51][52][53][54][55][56][57][58] with one exception, 59 and implicates Enterococcus faecalis as an opportunistic pathogen in persistent apical periodontitis.…”

Efficacy of Bacteriophage Treatment on Pseudomonas aeruginosa Biofilms

“…One species identified as a cause of persistent disease in endodontics is Pseudomonas aeruginosa (63)(64)(65)(102)(103)(104)(105) aeruginosa biofilms were susceptible to selected antibiotics and that increased resistance to antibiotic was typical of those that were grown for 48h or longer (147,149,150).…”

“…This method was chosen based on previous studies (6,31,60,63,65,104,132,155) that used paper points as their main method to extract the contents inside the root canal system. The paper points were specifically chosen to address the planktonic bacteria within the root canal.…”