Root Canal Microbiota of Teeth with Chronic Apical Periodontitis

Abstract

Samples from infected root canals of 43 teeth with chronic apical periodontitis were analyzed for the presence and relative levels of 83 oral bacterial species and/or phylotypes using a reverse-capture checkerboard hybridization assay. Associations between the most frequently detected taxa were also recorded. The most prevalent taxa were Olsenella uli (74%), Eikenella corrodens (63%), Porphyromonas endodontalis (56%), Peptostreptococcus anaerobius (54%), and Bacteroidetes oral clone X083 (51%). When prevalence was considered only for bacteria present at levels >10 5 , Bacteroidetes clone X083 was the most frequently isolated bacterium (37%), followed by Parvimonas micra (28%), E. corrodens (23%), and Tannerella forsythia (19%). The number of target taxa per canal was directly proportional to the size of the apical periodontitis lesion, with lesions >10 mm in diameter harboring a mean number of approximately 20 taxa. Several positive associations for the most prevalent taxa were disclosed for the first time and may have important ecological and pathogenic implications. In addition to strengthening the association of several cultivable named species with chronic apical periodontitis, the present findings using a large-scale analysis allowed the inclusion of some newly named species and as-yet-uncultivated phylotypes in the set of candidate pathogens associated with this disease.Chronic apical periodontitis is arguably one of the most common forms of biofilm-induced diseases that affect humans (9). The disease develops after dental pulp necrosis and infection as a result of caries, trauma, or iatrogenic clinical procedures. The environmental conditions in the necrotic root canal are conducive to the establishment of a microbiota conspicuously dominated by anaerobic bacteria. Bacterial profiles of the endodontic microbiota vary from individual to individual (37); i.e., each individual harbors a unique microbiota in terms of species richness and abundance. This indicates that apical periodontitis has a heterogeneous etiology, where no single species can be considered to be the main endodontic pathogen, and multiple bacterial combinations can play a role in disease causation.Early studies of the microbiota associated with apical periodontitis were conducted using broad-range culture methods. Those studies were followed by a generation of studies employing molecular detection methods such as species-specific PCR and the original checkerboard DNA-DNA hybridization assay to target cultivable bacteria previously isolated from infected canals or from other oral diseased sites. These methods allowed the inclusion of some culture-difficult species in the set of candidate endodontic pathogens. The adoption of 16S rRNA gene clone library analysis allowed an even more comprehensive broad-range investigation of bacterial communities in endodontic infections. By this technique, not only cultivable species but also as-yet-uncultivated and uncharacterized bacteria can be identified. Studies using the 16S rRNA gene clone library ana...

Response of Subgingival Bacteria to Smoking Cessation

“…The implication of this finding is not clear; while it appears to be logical that smoking cessation influences the subgingival microbiome through several different mechanisms, it is possible that P. gingivalis is metabolically more versatile than P. endodontalis. P. endodontalis is a Gramnegative, obligate anaerobe that has previously been identified in periodontal pockets as well as endodontic infections (12,21,23). This strong temporal association between smoking and the prevalence of P. endodontalis suggests that determining the role of this species in the plaque biofilm could have important implications for monitoring periodontitis in smokers.…”

Novel Model for Multispecies Biofilms That Uses Rigid Gas-Permeable Lenses

“…In vivo studies support that individual species in the multispecies oral biofilms are added sequentially, and variation in their accretion leads to differences in composition and spatial distribution (35,36). These processes in some ways reflect the in vivo observations of changes in proportions of proposed pathogenic species related to the initiation of periodontal disease (31,43). However, characteristics of host responses to these biofilms and the complex multifactorial biological influences also contribute to the individual outcome of disease (26,29).…”

Influência de medicações intracanal utilizadas em procedimentos endodônticos regenerativos na sobrevivência de células da papila apical in vitro

“…Enterococcus faecalis é comumente encontrado em lesões periapicais persistentes e seu papel na indução da doença periapical ainda não é claramente elucidado, por isso a importância da escolha pelo LTA (Sedgley et al, 2006;Roças;. Especula-se que a resposta celular a LTA seja desencadeada a partir da interação desta molécula com receptores de imunidade inata (Toll-like receptor TLR2/ TLR6 (Jin et al, 2007), comumente presentes em células residentes de tecidos conjuntivos (Morandini et al, 2013).…”

“…Como sabemos, os procedimentos endodônticos regenerativos são indicados para pacientes com dentes com polpa necrosada e com rizogênese incompleta, condição que é resultante de um processo inflamatório e colonizado por microrganismos. A importância de microrganismos na etiopatogenia da doença periapical já vem sendo amplamente elucidada pela literatura (Kakehashi et al, 1965;Moller et al, 2004;Roças, 2008). Mais de 40 espécies bacterianas já foram isoladas de canais radiculares de dentes com necrose pulpar (Zoletti et al, 2006;Roças;Siqueira Jr, 2010).…”

“…Enterococcus faecalis está relacionada às lesões periapicais que não regridem após a antissepsia realizada durante o tratamento endodôntico (Kaufman et al, 2005;Sedglay et al, 2006;Williams et al, 2006;Zoletti et al, 2006;Roças; (Signoretto et al, 2000). E. faecalis é uma bactéria Gram positiva e seu LTA é considerado um fator de virulência importante (Signoretto et al, 2000;Bruserud et al, 2004;Kayaoglu;Orstavik, 2004;Sipert, 2007;Baik et al, 2008).…”