It is reasonable to realize that disease severity, based on intensity of signs and symptoms, or response to treatment may be related to the bacterial community composition. Microbial involvement with treatment failures is supported by two strong evidence-based arguments. Bacteriology of dental abscesses of endodontic origin. Selected endodontic pathogens in the apical third of infected root canals: Root canal-treated teeth are about nine times more likely to harbor E. Primary infections Primary infections are caused by microorganisms that colonize the necrotic pulp tissue. Molecular methods have been largely used for profiling bacterial communities in diverse environments 16 , and one of their greatest advantages in this regard reside in the ability of including as-yet-uncultivated bacteria in the analysis
The fact that E. The pervasive effects of an antibiotic on the human gut microbiota, as revealed by deep 16S rRNA sequencing. Author information Article notes Copyright and License information Disclaimer. In advanced stages of the infectious process, bacterial organizations resembling biofilms can be observed adhered to the dentinal root canal walls 9 — 11 Fig. Herpesviruses in endodontic pathoses: Microbial diversity in endodontic infections has been consistently assessed by anaerobic culturing and culture-independent molecular biology methods.
Influence of residual bacteria on periapical tissue healing after chemomechanical treatment and root filling of experimentally infected monkey teeth. Table 1 Distinctive features of the microbiota associated with different types of endodontic infections. Advances in knowledge and technology open the perspectives for many questions to be answered and consequently many periodonttis to be raised in the near future.
Examples include open-ended techniques, such as pyrosequencing and metagenomic approaches —and closed-ended techniques, such as DNA microarrays using hundreds to even thousands of taxon-specific probes — Some gram-negative anaerobic bacteria have been suggested to be involved with symptomatic lesions 2264573 — 76but the same species may also be present in somewhat similar frequencies in asymptomatic cases 4347 — 50 Search and download doctoral PHD dissertations from Sweden.
This might restrict the focus to some microbial product combinations instead of species combinations, considering the very likely possibility that the dissertation may reach a broader spectrum of variability than the former.
However, a recent study using a histobacteriologic technique managed to detect bacteria in virtually all cases of post-treatment disease Reduced diversity of faecal microbiota in Crohn’s disease revealed by a metagenomic approach.
Effects of periodontitiis, irrigation and dressing with calcium hydroxide on infection in pulpless teeth with periapical bone lesions.
Collectively, more than different microbial taxa have been identified in endodontic samples from teeth with different forms of apical periodontitis. Real-time quantitative polymerase chain reaction and culture analyses of Enterococcus faecalis in root canals. In these cases, 1—5 species can be detected per canal, with counts reaching 10 2 —10 5 cells per sample 294193— Diversity of spirochetes in endodontic infections.
All these findings indicate that the microbiota of root canal-treated teeth with apical periodontitis is more complex than previously anticipated by culture studies.
Cytomegalovirus and Epstein-Barr virus are associated with symptomatic periapical pathosis.
Exploiting molecular methods to explore endodontic infections: Secondary infections are caused by microorganisms that were not present in the primary infection, but aical were introduced in the root canal at some time after professional intervention. Clone library analyses of primary endodontic infections reveal that a significant proportion of the detected taxa consist of phylotypes that remain to be cultivated and phenotypically characterized 26 Apical actinomycosis, which is caused by Actinomyces species or P.
Although fungi, archaea, and viruses have been found in association with some forms of apical periodontitis, bacteria are the main microbial etiologic agents of this disease. Molecular biology methods have caused a great impact in the knowledge of the bacterial diversity in endodontic infections In addition to bacteria, fungi and archaea have been only occasionally found in intraradicular infections 53132while herpesviruses and HIV have been detected in apical periodontitis lesions 433 — Disseertation acute conditions may evolve to an abscess, disserttion in some cases can spread to head and neck spaces to establish a life-threatening condition.
Thus far, there is no strong evidence reporting on the specific involvement of a single species with any particular aplcal or symptom of apical periodontitis.
In other words, while associations of any specific species with any form of apical periodontitis is seldom, if ever, observed, the bacterial community profiles seem to follow some patterns related to the different presentations of apical periodontitis Eur J Oral Sci. This concept is applicable to all three major oral infectious diseases — caries, marginal periodontitis, and apical periodontitis 13 — Therefore, there is a current trend to include apical periodontitis in the group of human infectious diseases caused by bacterial biofilms.
Again, identification of specific pathogen or molecular patterns related to treatment outcome may probably be the best way to establish tests to serve as a more accurate surrogate outcome.
Light and electron microscopic studies of root canal flora and periapical lesions. This is in agreement with the community-as-pathogen concept already discussed.
Overall, the bacterial density per canal varies from 10 3 to 10 8 22939 — As for flare-ups, the evidence of specificity is even weaker, although there are some reports of involvement of gram-negative anaerobes, such as black-pigmented rods and F.