Research progress on the pathogenesis and treatment of Enterococcus faecalis in pulp periapical disease / 口腔疾病防治

@#Enterococcus faecalis is an important pathogen in pulp periapical disease that has been widely studied in recent years. A large number of studies have shown that the high detection rate of Enterococcus faecalis in root canals with persistent or secondary infection after root canal therapy is closely related to the failure of root canal therapy. The presence of Enterococcus faecalis in periapical pulp disease is related to its pathogenicity and virulence factors. Enterococcus faecalis can directly invade host tissues or induce immune inflammation in host tissues, resulting in periapical pulp tissue damage and lesions. Enterococcus faecalis has a strong tolerance to conventional root canal antibiotics and disinfection methods and is difficult to completely remove from the complex root canal system. How to fight Enterococcus faecalis infection has become an important direction in the treatment of pulp periapical disease. This article reviews the pathogenic mechanism of Enterococcus faecalis infection in pulp periapical disease and the progress in its treatment.

A periodontite apical como fator de risco às manifestações sistêmicas: uma perspectiva histórica atualizada / Apical periodontitisas a risk factor to systemic manifestations: a updated historical perspective

Objetivo: O objetivo deste trabalho foi revisar a literatura científica pertinente, dando enfoque ao tratamento endodôntico e dentes portadores de necrose pulpar associados à periodontite apical como fator de risco às manifestações sistêmicas, desde a teoria da infecção focal até os dias atuais. Metodologia: Empregou-se fontes de catalogação bibliográfica identificadas eletronicamente pelo MEDLINE, até setembro de 2018. Os artigos relacionados pela busca eletrônica foram selecionados, por três revisores independentes, avaliando os critérios de inclusão e exclusão. Resultados: A busca apresentou 107 artigos, sendo que destes, 17 estudos satisfizeram os critérios de inclusão, o que possibilitou a análise dos dados. Conclusão: Muitos dos preceitos da teoria da infecção focal estão sendo reerguidos por pesquisas que mostram cada vez mais a existência de associações entre patologias endodônticas e sistêmicas.

Objective: The aim of this work was to review the pertinent scientific literature, focusing on endodontic treatment and teeth with pulp necrosis associated with apical periodontitis as a risk factor for systemic manifestations, from the focal infection theory to the present day. Methodology: The sources of bibliographic cataloging electronically identified by MEDLINE were used until September 2018. Articles related to the electronic search were selected by three independent reviewers, evaluating the inclusion and exclusion criteria. Results: The search presented 107 articles, of which, 17 studies met the inclusion criteria, which made it possible to analyze the data. Conclusion: Many of the precepts of the focal infection theory are being reinstated by research that increasingly shows the existence of associations between endodontic and systemic pathologies.

Quantitative evaluation of live Enterococcus faecalis in failed endodontic root-well-filled teeth / 实用口腔医学杂志

Objective:To analyse viable Enterococcus faecalis(E.faecalis)in root-well-filled teeth associated with failed endodontic treatment by using propidium monoazide (PMA)in combination with real time qPCR.Methods:Bacterial samples were extracted from 34 root-canal-treated teeth with post-treatment apical periodontitis.Each sample was separated into 2 different tubes.PMA was added to one of the tubes,and the other was left untreated.Then,DNA extraction and qPCR were performed.Results:E.faecalis was found in 20 of the 34 samples(58.8%).In PMA treated and none-treaten samples the Ct value of E.faecalis was 25.1 2 ±2.04 and 24.62 ± 2.02 respectively(P =0.001 ).Conclusion:PMA may be feasible in differentiating viable and dead Enterococcus faecalis cells.

Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls. In vitro SEM study

OBJECTIVES: This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. MATERIALS AND METHODS: Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). RESULTS: Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. CONCLUSIONS: Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules.

A review of microbiological root canal sampling: updating an emerging picture / Uma revisão de amostragem microbiológica de canal radicular: atualizando um quadro emergente

The significance of microorganisms in root canals with regard to the aetiology of periapical infection and the need for crucial bacteria control during treatment are undeniable. In this study, we report and discuss a review of the literature on Microbiological Root Canal Sampling (MRS). The procedure is analyzed in detail, discussing its powers, limitations and the influence of sample collection procedures on the incidence of true and false positive results. Data sources: MEDLINE/PUBMED, B-On and library files of Oporto University were accessed. Selection: Papers were selected using the keywords: “root ca¬nal sampling”; “apical periodontitis”; “endodontic pathogens”; “root canal infection”; “Culture”; “molecular biology”. The references were selected under inclusion criteria such as English language, accessibility, relevance to the theme and scientific rigor. Conclusions: This review illustrated the absolute need to adhere to strict methodology procedures if valid samples are to be obtained. A combination of Culture and molecular identification approaches have confirmed the polymicrobial nature of endodontic infections with a predominance of anaerobic bacteria. Nucleic acid-based techniques provide significant additional information particularly regarding the not-yet-cultivable species of the microbial community, but greatly increase the budget of the procedure. Thus, assessment of the endodontic microflora, in the context of a polymicrobial biofilm ecosystem, and its relevance to endodontic treatments must rely in the complementariness of Culture and Metagenomics approaches as they are neither mutually exclusive nor competitive, but strongly complementary...

A importância de microrganismos em canais radiculares no que diz respeito à etiologia da infecção periapical e a necessidade de controlar bactérias durante o tratamento são incontestáveis. Neste estudo, relata-se e discute-se uma revisão da literatura sobre a amostragem microbiológica de canal radicular. O procedimento é analisado em detalhes, discutindo suas atribuições, limitações e influência de procedimentos de coleta de amostra sobre a incidência de verdadeiros e falsos resultados positivos. Fontes de dados: Foram usados MEDLINE/PubMed, B-On e arquivos da biblioteca da Universidade do Porto. Seleção: Os trabalhos foram selecionados utilizando as palavras-chave: “root canal sampling”; “apical periodontitis”; “endodontic pathogens”; “root canal infection”; “Culture”; “molecular biology”. As referências foram selecionadas de acordo com critérios de inclusão como o idioma inglês, acessibilidade, relevância para o tema e rigor científico. Conclusões: Esta revisão ilustrou a absoluta necessidade de aderir aos procedimentos metodológicos rigorosos se se pretende obter amostras válidas para análise. Uma combinação de cultura e abordagens de iden¬tificação molecular confirmaram a natureza polimicrobiana das infeções endodônticas com predominância de bactérias anaeróbias. Técnicas baseadas em ácidos nucleicos fornecem informação adicional significativa, particularmente em relação às espécies não cultiváveis da comunidade microbiana, mas aumentam muito o orçamento do procedimento. Assim, a avaliação da microflora endodôntica, no contexto de um ecossistema polimicrobiano em biofilme, e sua relevância para tratamentos endodônticos devem confiar na complementaridade entre a abordagem de cultura e de metagenômica, pois não são mutuamente exclusivas nem competitivas, mas fortemente complementares...

Residual antibacterial activity of chlorhexidine digluconate and camphorated p-monochlorophenol in calcium hydroxide-based root canal dressings

The purpose of this study was to evaluate the residual antibacterial activity of several calcium hydroxide [Ca(OH)2]-based pastes, placed in root canals of dogs' teeth with induced chronic periapical lesions. Root canals were instrumented with the ProFile rotary system and filled with 4 pastes: G1 (n=16): Ca(OH)2 paste + anesthetic solution; G2 (n=20): Calen® paste + camphorated p-monochlorophenol (CMCP); G3 (n=18): Calen®; and G4 (n=18): Ca(OH)2 paste + 2 percent chlorhexidine digluconate. After 21 days, the pastes were removed with size 60 K-files and placed on Petri plates with agar inoculated with Micrococcus luteus ATCC 9341. Pastes that were not placed into root canals served as control. After pre-diffusion, incubation and optimization, the inhibition zones of bacterial growth were measured and analyzed by Mann-Whitney U test at 5 percent significance level. All pastes showed residual antibacterial activity. The control samples had larger halos (p<0.05). The mean residual antibacterial activity halos in G1, G2, G3 and G4 were 7.6; 10.4; 17.7 and 21.4 mm, respectively. The zones of bacterial growth of G4 were significantly larger than those of G1 and G2 (p<0.05). In conclusion, regardless of the vehicle and antiseptic, all Ca(OH)2-based pastes showed different degrees of measurable residual antibacterial activity. Furthermore, unlike CMCP, chlorhexidine increased significantly the antibacterial activity of Ca(OH)2.

Este estudo objetivou mensurar a atividade anti-bacteriana residual de várias pastas à base de hidróxido de cálcio [Ca(OH)2], após permanecerem em canais radiculares de cães com lesões periapicais crônicas induzidas. Os canais radiculares foram instrumentados com o sistema Profile e preenchidos com quatro diferentes pastas: G1-Ca(OH)2 p.a./solução anestésica (n=16), G2-Calen®/PMCC (n=20), G3-Calen® (n=18) e G4-Ca(OH)2 p.a./solução de digluconato de clorexidina a 2 por cento (n=18). Transcorridos 21 dias, amostras foram recuperadas dos canais radiculares com limas Kerr #60 e colocadas em placas de Petri com ágar semeado com Micrococcus luteus ATCC 9341. Pastas não aplicadas nos canais radiculares serviram como controle. Após pré-difusão, incubação e otimização, as zonas de inibição do crescimento bacteriano foram mensuradas e analisadas pelo teste de Mann-Whitney (a<0.05). Verificou-se que todas as pastas apresentaram ação antibacteriana residual, com maiores halos para as amostras-controles. As médias dos halos de inibição para G1, G2, G3 e G4 foram 7,6; 10,4; 17,7 e 21,4 mm, respectivamente. Os halos de inibição de G4 foram significativamente superiores as de G1 e G2 (p<0.05). Portanto, independentemente do veículo, todas as pastas à base de Ca(OH)2 determinaram, em diferentes magnitudes, atividade anti-bacteriana residual mensurável. Ademais, diferentemente do PMCC, a solução de digluconato de clorexidina a 2 por cento ampliou significativamente, a atividade anti-bacteriana residual do hidróxido de cálcio.