Three Dimensional mapping of the root apex: distances between apexes and anatomical structures and external cortical plates

Abstract This study aimed to determine the mean distances between apexes of the maxillary posterior teeth and the maxillary sinus, between apexes of the mandibular posterior teeth and the mandibular canal, and between the root apexes of all teeth and the adjacent cortical plates. A total of 800 cone-beam computed tomography (CBCT) scans (400 maxillary and 400 mandibular) were obtained from patients indicated for several treatments. The proximity between apexes and anatomical structures, and the relationship between apexes and adjacent cortical plates were assessed together with the risk of over-instrumentation. Paired-sample comparisons were performed by using the paired t-test. The means were compared by ANOVA, Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. a) Most of the apexes classified as A (high-risk proximity) were observed in maxillary first and second molars, in mandibular first and second molars, and in second premolars in relation to near anatomical structures. b) A predominance of class A (86.42%) was noticed in the first premolars, between apexes of maxillary teeth and adjacent cortical plates. c) The distance between apexes of mandibular teeth and buccal cortical plates showed a predominance of medium-risk proximity (B) in all the groups, except the first premolars, with the highest risk (82.22%), and the second molars, with low-risk proximity (C) to distal and mesiobuccal apexes (91.77% and 89.62%). CBCT images are important for endodontic diagnosis and treatment, since many teeth have high risk proximity to near anatomical structures and adjacent cortical plates.

Microbial profile and endotoxin levels in primary periodontal lesions with secondary endodontic involvement

Abstract This study was carried out to investigate the microbial profile and endotoxin levels of endodontic-periodontal lesions of periodontal origin. Periodontal and endodontic samples were taken from periodontal pockets and necrotic root canals of 10 teeth with endodontic-periodontal lesions. Evidencing of 40 different bacterial species were determined in each endodontic and periodontal sample using the checkerboard DNA-DNA hybridization method and Kinetic chromogenic LAL assay was used for quantification of endotoxins. Fisher's exact test correlated the bacterial species with the endodontic or periodontal microbiota. The endotoxin levels (EU/mL) found in samples of the root canal and periodontal pocket were compared by the Wilcoxon test (p<0.05). Bacteria and LPS units were found in 100% of the endodontic and periodontal samples. The species E. faecium, P. acnes, G. morbillorum, C. sputigena and L. buccalis were strongly correlated with the endodontic microbiota and P. nigrescens with the periodontal microbiota. P. intermedia, P. endodontalis and V. parvula were more prevalent in both endodontic and periodontal microbiots. The endotoxin levels in the periodontal pocket (89600 EU/mL) were significantly higher than in the root canal (2310 EU/mL). It was concluded that the microbiota present in the periodontal and endodontic tissues is similar, with a higher prevalence of species of the orange complex and a higher level of endotoxin in the periodontal pockets.

Resumo Este estudo foi realizado para investigar o perfil microbiano e os níveis de endotoxina de lesões endoperiodontais de origem periodontal. Amostras periodontais e endodônticas foram obtidas de bolsas periodontais e canais radiculares necróticos de 10 dentes com lesões endoperiodontais. A investigação de 40 espécies bacterianas diferentes foram determinadas em cada amostra endodôntica e periodontal usando o método de hibridização de DNA-DNA (checkerboard) e o ensaio cinético cromogênico LAL foi usado para quantificação de endotoxinas. O teste exato de Fisher correlacionou as espécies bacterianas com a microbiota endodôntica ou periodontal. Os níveis de endotoxina (EU/mL) encontrados nas amostras do canal radicular e na bolsa periodontal foram comparados pelo teste de Wilcoxon (p<0,05). Bactérias e unidades de LPS foram encontradas em 100% das amostras endodônticas e periodontais. As espécies E. faecium, P. acnes, G. morbillorum, C. sputigena e L. buccalis foram fortemente correlacionadas com a microbiota endodôntica e P. nigrescens com a microbiota periodontal. P. intermedia, P. endodontalis e V. parvula foram mais prevalentes em ambas microbiotas endodôntica e periodontal. Os níveis de endotoxina na bolsa periodontal (89600 EU/mL) foram significativamente maiores do que no canal radicular (2310 EU/mL). Concluiu-se que a microbiota presente nos tecidos periodontal e endodôntico é semelhante, com maior prevalência de espécies do complexo laranja e maior nível de endotoxina nas bolsas periodontais.

Effect of edta and qmix ultrasonic activation on the reduction of microorganisms and endotoxins in ex vivo human root canals

Abstract The present study aimed to compare the effectiveness of QMiX and 17% EDTA associated to passive ultrasonic irrigation (PUI) or manual agitation (MA) on the reduction of E. faecalis, E. coli and LPS from root canals. Forty single rooted human teeth were randomly divided into four groups (n=10), according to the final irrigation protocol: EDTA+MA, QMiX+MA, EDTA+PUI, QMiX+PUI. Sample collections were obtained from the root canal content immediately before preparation (baseline-S1), after instrumentation (S2), after final irrigation protocol (S3) and 7 days after instrumentation and final irrigation (S4). The antimicrobial effectivity and on endotoxin content were analyzed by culture procedure (CFU/mL) and LAL assay (EU/mL), respectively. The results were statistically analyzed by Kruskal-Wallis and Friedman test (α=5%). QMiX+MA and QMiX+PUI reduced 100% of E. coli and E. faecalis bacteria and also prevented E. faecalisregrowth at S4. EDTA significantly reduced E. coli, but it was not effective in reducing E. faecalis. All protocols reduced EU/mL when compared to S1, however at S4 there was a significant reduction of EU/mL only in the QMiX+MA and QMiX+PUI groups in relation to S3 and S2, respectively. Final irrigation with QMiX associated with MA or PUI had superior antibacterial efficacy compared to EDTA, eliminating 100% of E. coli and E. faecalis strains. In addition, QMiX+PUI reduced 97.61% of the initial content of LPS.

Resumo O presente estudo objetivou comparar a eficácia do QMiX e do EDTA 17% associado à irrigação ultrassônica passiva (PUI) ou agitação manual (MA) na redução de E. faecalis, E. coli e LPS de canais radiculares. Quarenta dentes humanos unirradiculares foram divididos aleatoriamente em quatro grupos (n = 10), de acordo com o protocolo final de irrigação: EDTA+MA, QMiX+MA, EDTA+PUI, QMiX+PUI. Coletas das amostras foram obtidas a partir do conteúdo do canal radicular imediatamente antes do preparo (inicial-S1), após a instrumentação (S2), após o protocolo final de irrigação (S3) e 7 dias após a instrumentação e irrigação final (S4). A eficácia antimicrobiana e o conteúdo de endotoxina foram analisados ​​por procedimento de cultura (UFC/mL) e ensaio LAL (EU/mL), respectivamente. Os resultados foram analisados estatisticamente pelo teste de Kruskal-Wallis e Friedman (α = 5%). QMiX+MA e QMiX+PUI reduziram 100% das bactérias E. coli e E. faecalis e também preveniram a recolonização de E. faecalis em S4. O EDTA reduziu significativamente E. coli, mas não foi eficaz na redução de E. faecalis. Todos os protocolos reduziram EU/mL quando comparados com S1, no entanto, no S4 houve uma redução significativa de EU/mL apenas nos grupos QMiX+MA e QMiX+PUI em relação a S3 e S2, respectivamente. A irrigação final com QMiX associada a MA ou PUI apresentou eficácia antibacteriana superior em relação ao EDTA, eliminando 100% das cepas de E. coli e E. faecalis. Além disso, QMiX+PUI reduziu 97,61% do conteúdo inicial de LPS.

Comparison of two rotary systems in bacteria/lps removal from endodontic infections: randomized clinical trial

Abstract: This clinical study compared the effectiveness of two rotary systems: HyFlex CM (Coltene-Whaledent, Altstetten, Switzerland) and ProTaper Next (Dentsply Sirona, Ballaigues, Switzerland) on the removal of cultivable bacteria and endotoxins from primarily infected root canals. This study was designed as a randomized single-blinded, 2-arm, clinical trial. Twenty-four primarily infected root canals were selected and randomly divided into 2 groups: HyFlex CM (n = 12); and ProTaper Next (n = 12). Samples were collected before and after the biomechanical preparation and inoculated in specific flasks. Irrigation was performed using 2.5% sodium hypochlorite. A kinetic turbidimetric lysate assay of limulus amoebocytes was used to quantify endotoxins. Microbiological culture technique was used to determine the count of bacterial colony forming units (CFU/mL). Data collected were statistically analyzed using SigmaPlot 12.0 for Windows. The Two-Way ANOVA statistical test was performed and the level of significance was 5%. In the samples before the biomechanical preparation, cultivable bacteria and endotoxins were evidenced in 100% of the cases. The culture analysis revealed that there was no statistically significant difference in the bacterial reduction between the two instrumentation systems. Endotoxins were present in 100% of the canals after instrumentation and there was no statistical difference between the two systems in endotoxin reduction. Thus, it was concluded that both instrumentation systems were effective in reducing root canal bacteria and endotoxins with primary endodontic infection and that there was no statistical difference between them. However, no system was able to eliminate 100% of the bacteria and their by-products.

Anticoagulant effects of phytotherapeutic drugs and their importance in surgical dental procedures / Efeitos anticoagulantes de drogas fitoterapicas e sua importância em procedimentos odontológicos cirúrgicos

ABSTRACT Phytotherapeutic drugs are plant-derived products with medicinal properties. They are used for treating or preventing several diseases. However, patients who use these substances and even health professionals are unaware of their negative effects. One of the most common negative effects of phytotherapeutic drugs reported in the literature is the inhibition of natural coagulation factors in the human body. Therefore, the aim of this study was to perform a brief review of the literature concerning the anticoagulant effects of phytotherapeutic drugs and their importance in surgical dental procedures. Preventive measures, clarification and monitoring of patients taking phytotherapeutic drugs are recommended before performing surgical dental procedures, in order to prevent against complications such as hemorrhage.

RESUMO Fitoterápicos são produtos derivados de plantas com propriedades medicinais. Eles são utilizados para o tratamento ou a prevenção de diversas doenças. No entanto, os pacientes que fazem uso destas substâncias, na sua grande maioria, desconhecem seus efeitos negativos. Portanto, o objetivo deste estudo foi realizar uma breve revisão de literatura sobre os efeitos anticoagulantes de fitoterápicos e sua importância diante da realização de procedimentos odontológicos cirúrgicos. Medidas de prevenção, esclarecimento e acompanhamento de pacientes que se utilizam destes medicamentos são recomendados antes da realização destes procedimentos a fim de prevenir complicações como processos hemorrágicos.

Diversidade bacteriana nas infecções endodônticas primárias e secundárias/persistentes através da técnica de Checkerboard DNA-DNA Hybridization / Bacterial diversity in primary and secondary/persistent endodontic infections by Checkerboard DNA-DNA Hybridization Technique

Introdução: os métodos moleculares de diagnóstico apresentam como uma das principais vantagens a detecção de microrganismos por meio do DNA bacteriano, levando a uma caracterização microbiana mais acurada. Objetivo: o presente estudo visou investigar a diversidade bacteriana presente nas infecções endodônticas primárias e secundárias/persistentes, comparando o perfil das comunidades microbianas existentes antes e após a terapia endodôntica. Métodos: as amostras microbiológicas foram coletadas antes (T1) e após terapia endodôntica (T2), utilizando cone de papel estéril/apirogênico em dentes com infecções endodônticas primárias (n = 10) e secundárias / persistentes (n = 10). A presença e os níveis de 40 espécies bacterianas nas infecções endodônticas foram investigados por meio da técnica de Checkerboard DNA-DNA Hybridization. Resultados: nas infecções endodônticas primárias em T1, as espécies encontradas em maiores níveis foram P. micra, F. nucleatum sp. nucleatum, S. constellatus, P. gingivalis, G. morbillorum, P. endodontalis, T. denticola, P. acnes, S. gordonii, S. mitis, V. parvula e C. rectus. Em T2, as bactérias mais encontradas foram P. micra, S. oralis e P. acnes. Nas infecções endodônticas secundárias em T1, as espécies mais frequentemente encontradas foram P. acnes, P. micra, S. constellatus, G. morbillorum, C. rectus, A. naeslundii, S. mitis e S. oralis. Em T2, as espécies mais encontradas foram Enterococcus faecalis e Propionibacterium acnes. Conclusão: o presente estudo confirmou comunidades microbianas distintas em infecções endodônticas primárias e secundárias. Além disso, os procedimentos clínicos endodônticos mostraram-se eficazes na redução significativa da prevalência, dos níveis de detecção e na diversidade bacteriana.

Diagnóstico diferencial da sinusite de origem odontológica por meio da tomografia computadorizada / Differential diagnosis of dental sinusitis with the aid of computed tomography

O objetivo do presente artigo é apresentar três casos clínicos com diagnóstico de sinusite de origem odontológica, ou síndrome endo-antral, um quadro inflamatório infeccioso de origem endodôntica que acomete dos tecidos e mucosa do seio maxilar adjacentes aos ápices radiculares.Os casos apresentados chamam a atenção para a dificuldade do diagnóstico apenas coma radiografia periapical e a importância da tomografia computadorizada como recurso auxiliar.

The aim of the current article is to report three clinical cases diagnosed as sinusitis of dental origin, or endo-antral syndrome, an inflammatory condition of endodontic infection origin that affects the tissues and mucosa of the adjacent maxillary sinus up to the root apex. The presented cases draw attention to the difficulty of diagnosis only with periapical radiography and the importance of computed tomography as an auxiliary resource.

Investigation of Bacterial Contents From Persistent Endodontic Infection and Evaluation of Their Inflammatory Potential

Abstract This clinical study investigated and quantified cultivable bacteria and their levels of endotoxins in persistent endodontic infection, determining their antigenicity against macrophages and fibroblast cells by IL-1β and TNF-α secretion and evaluating their relationship with clinical and radiographic features. Samples from the root canals were obtained after root filling removal. Culture techniques were used to determine the bacterial count and the endotoxins were determined by LAL-assay. PCR analysis (16S rDNA) was used for bacterial detection. Raw 264.5 macrophages and V79 fibroblast were stimulated with endodontic contents. ELISA assay measured the amounts of IL-1ß/TNF-?#61537; secretion. Bacteria and endotoxin medians were 1.24x105 CFU/mL and 9.62 EU/mL, respectively. Porphyromonas endodontalis was the most frequently detected species. Higher levels of endotoxins were found in teeth with pain on palpation (23.56 EU/mL) rather than in its absence (8.21 EU/mL). Larger areas of bone destruction were related to higher levels of endotoxins and IL-1β and TNF-α secretion. The study findings revealed the presence of Gram-negative bacteria species in persistent endodontic infection, with their endotoxins related to both severity of bone destruction and development of symptomatology. Moreover, larger areas of bone destruction were related to higher levels of IL-1β and TNF-α secreted by macrophages and fibroblast cells.

Resumo Este estudo clínico investigou e quantificou bactérias cultiváveis e seus níveis de endotoxinas na infecção endodôntica persistente, determinando a sua antigenicidade contra macrófagos e células de fibroblastos através de IL-1β e TNF-α; e avaliando sua relação com características clínicas e radiográficas. As amostras dos canais radiculares foram obtidas após a desobturação. Técnicas de cultura foram utilizadas para determinar a contagem de bactérias e a quantificação de endotoxinas foram determinadas por ensaio de LAL. Análise por PCR (16S rDNA) foi utilizada para a detecção bacteriana. Células 264,5 macrófagos e fibroblastos V79 foram estimuladas com conteúdo endodôntico. IL-1β e TNF-α produzidas pelas células avaliadas foram medidas por ensaio de ELISA. As medianas de bactérias e endotoxinas foram 1,24x105 UFC/mL e 9,62 EU/mL, respectivamente. Porphyromonas endodontalis foi a espécie mais frequentemente detectada. Níveis mais elevados de endotoxinas foram encontrados em dentes com dor à palpação (23,56 EU/mL) quando comparado a sua ausência (8,21 EU/mL). Maiores áreas de destruição óssea foram relacionados com níveis mais elevados de endotoxinas e IL-1β e TNF-α. O estudo revelou presença de espécies de bactérias Gram-negativas em infecção endodôntica persistente, com níveis elevados de endotoxinas relacionados a maior destruição óssea periapical e presença de sintomatologia. Além disso, grandes áreas de destruição óssea foram relacionados com níveis mais elevados de IL-1β e TNF-α secretadas por macrófagos e fibroblastos.

Investigation in vivo of Enterococcus faecalis in endodontic retreatment by phenotypic and genotypic methods / Investigação in vivo de Enterococcus faecalis em retratamento endodôntico por meio de métodos fenotípicos e genotípicos

This study aimed to investigate the prevalence of E. faecalis in root-filled canals using culture and molecular approaches. It was evaluated the antimicrobial susceptibility to different antibiotics and the virulence factors of E. faecalis isolates. Microbial samples were taken from thirty root-filled canals. Culture methods and 16S rDNA assay were used to identify E. faecalis. The antimicrobial susceptibility of E. faecalis was determined by MIC values using the E test. Cultivable strains of E. faecalis were investigated for virulence factors by PCR technique. E. faecalis were detected by culture (7/30), traditional PCR assay (13/30) and nested PCR (23/30). Both PCR were significantly more effective than culture in detecting E. faecalis (p < 0.05). All tested E. faecalis were highly sensitive to amoxicillin. Some strains of E. faecalis were resistant to antibiotics such as rifampicin (4/12), erythromycin (3/12) and azythromycin (8/12). The genes efaA and ace were detected in all isolates. The other virulence genes were found in 91.6 (gelE), 83.3 (asa), 25 (esp) and 16.6% (cylA). Strains of E. faecalis isolated from root-filled canals showed virulence factors related to adherence. They also showed resistance to some antibiotics commonly used in dentistry.

O objetivo deste estudo foi investigar a prevalência de E. faecalis em dentes tratados endodonticamente utilizando as técnicas de cultura e molecular. Foram avaliados a suscetibilidade antimicrobiana frente a diferentes antibióticos e os fatores de virulência de E. faecalis isolados. As amostras foram coletadas de 30 dentes tratados endodonticamente. Métodos de cultura e 16S rDNA foram utilizados para identificar E. faecalis. A suscetibilidade antimicrobiana de E. faecalis foi determinada por valores de MIC, utilizando o E test. Os fatores de virulência de cepas de E. faecalis cultiváveis foram investigados pela técnica de PCR. E. faecalis foram detectados por cultura (7/30), PCR tradicional (13/30) e nested PCR (23/30). Ambas as técnicas de PCR foram significativamente mais eficazes do que a cultura na detecção de E. faecalis (p < 0,05). Todos os E. faecalis testados foram altamente sensíveis à amoxicilina. Algumas cepas de E. faecalis foram resistentes a antibióticos, como a rifampicina (4/12), eritromicina (3/12) e azitromicina (8/12). Os fatores de virulência efaA e ace foram detectados em todos os isolados. Os outros genes de virulência foram encontrados em 91,6 (gelE), 83,3 (asa), 25 (esp) e 16,6% (cylA). As cepas de E. faecalis isoladas em dentes tratados endodonticamente mostraram fatores de virulência relacionados à adesão. Eles também apresentaram resistência a alguns antibióticos comumente utilizados na odontologia.

Monitoring the effectiveness of root canal procedures on endotoxin levels found in teeth with chronic apical periodontitis

Objective: The aim of this study was to monitor the effectiveness of root canal procedures by using different irrigants and intracanal medication on endotoxin levels found in root canals of teeth with chronic apical periodontitis. Material and Methods: Thirty root canals of teeth with pulpal necrosis associated with periapical lesions were selected and randomly divided into groups according to the irrigants used: GI - 2.5% NaOCl, GII - 2% chlorhexidine (CHX) gel, and GIII - saline solution (SS) (all, n=10). Samples were collected with sterile/apyrogenic paper points before (S1) and after root canal instrumentation (S2), after use of 17% ethylenediaminetetraacetic acid (EDTA) (S3), and after 30 days of intracanal medication (Ca(OH)2+SS) (S4). A turbidimetric kinetic Limulus Amebocyte Lysate assay was used for endotoxin measurement. Results: Endotoxins were detected in 100% of the root canals investigated (30/30), with a median value of 18.70 EU/mL. After S2, significant median percentage reduction was observed in all groups, irrespective of the irrigant tested: 2.5% NaOCl (99.65%) (GI), 2% CHX (94.27%) (GII), and SS (96.79%) (GIII) (all p<0.05). Root canal rinse with 17% EDTA (S3) for a 3-minute period failed to decrease endotoxin levels in GI and a slight decrease was observed in GII (59%) and GIII (61.1%) (all p>0.05). Intracanal medication for 30 days was able to significantly reduce residual endotoxins: 2.5% NaOCl (90%) (GI), 2% CHX (88.8%) (GII), and SS (85.7%) (GIII, p<0.05). No differences were found in the endotoxin reduction when comparing s2 and s4 treatment groups. Conclusion: Our findings demonstrated the effectiveness of the mechanical action of the instruments along with the flow and backflow of irrigant enduring root canal instrumentation for the endotoxin removal from root canals of teeth with chronic apical periodontitis. Moreover, the use of intracanal medication for 30 days contributed for an improvement ...

Evaluation of 0.5 percent peracetic acid and 2.5 percent sodium hypochlorite on smear layer removal of root canal instrumented by three rotary systems / Avaliação do ácido peracético a 0.5 por cento e do hipoclorito de sódio a 2.5 por cento na remoção da smear layer em canais instrumentados por três sistemas rotatórios

Objective: The aim of this study was to evaluate the effect of 0.5% peracetic acid solution and 2.5% sodium hypochlorite solution on smear layer removal of root canal walls after rotary instrumentation. Material & methods: Sixty single-rooted human teeth with standardized length had their canals instrumented by three rotary systems (Biorace, MTwo and Endowave), varying the irrigation solution, as follows (n=10): G1- Biorace System + 0.5% peracetic acid solution; G2- Biorace System + 2.5% sodium hypochlorite solution; G3- MTwo System + 0.5% peracetic acid solution; G4- MTwo System + 2.5% sodium hypochlorite solution; G5- Endowave System + 0.5% peracetic acid solution; G6- Endowave System + 2.5% sodium hypochlorite solution. After instrumentation, the roots were cleaved and the dentin walls were evaluated by SEM at x500 and x2000 magnification for assessing the cleaning of the root canals at the cervical, middle and apical thirds. The analyzed area was quantified according to the total number of tubules present and the percentage of open tubules at each region. Data were submitted to statistical analysis by ANOVA and Tukey tests, at the significance level of 5%. Results: There were no statistical significant differences among the experimental groups. In all groups the smear layer removal at cervical and medium thirds was higher than that of apical third. Conclusion: It was concluded that the cleaning obtained at the apical third was lower in all groups studied and neither the instrumentation technique nor the irrigating solution was able to promote total smear layer removal from root canal walls

Objetivo: O objetivo deste estudo foi avaliar o efeito do ácido peracético a 0,5% e do hipoclorito de sódio a 2,5% na remoção da smear layer das paredes do canal radicular após instrumentação com diferentes sistemas rotatórios. Material e métodos: Foram utilizados 60 dentes humanos unirradiculares que tiveram seus canais instrumentados de forma padronizada por três sistemas rotatórios (Biorace, MTwo e Endowave), variando a solução irrigadora utilizada, como segue (n = 10): G1 - Ácido peracético a 0,5% + Preparo Biomecânico (PBM) com Sistema Biorace; G2 - Hipoclorito de sódio a 2,5% + PBM com Sistema Biorace; G 3 - Ácido peracético 0,5% + PBM com Sistema Mtwo; G4 - Hipoclorito de sódio 2,5% + PBM com Sistema MTwo; G5 – Ácido peracético a 0,5% + PBM com Sistema Endowave; G6 - Hipoclorito de sódio a 2,5% + PBM com Sistema Endowave. Finalizada a instrumentação, as raízes foram clivadas e as paredes dentinárias foram avaliadas em MEV com aumento de 500x e 2000x nos terços cervical, médio e apical. A área analisada foi quantificada pelo número total de túbulos dentinários presentes e pela porcentagem de túbulos abertos na região avaliada. Os dados relativos à porcentagem de túbulos abertos foram submetidos à análise estatística utilizando os testes de ANOVA e Tukey com nível de significância de 5%. Resultados: Os resultados mostraram que não houve diferença estatisticamente significante entre os grupos experimentais. A remoção da smear layer foi maior nos terços cervical e médio em relação ao terço apical em todos os grupos. Conclusão: Nenhuma técnica de instrumentação ou solução irrigadora foi capaz de promover a remoção total da smear layer das paredes do canal radicular e a limpeza obtida no terço apical foi inferior em todos os grupos avaliados.

Investigation of virulence factors of Enterococcus faecalis strains isolated in secondary/ persistent infections / Investigação de fatores de virulência de estirpes de Enterococcus faecalis isoladas em infecções secundárias persistentes

More virulent strains may result from the acquisition of genes by genetic exchange, pathogenicity islands in several species encoding toxins, adhesion factors and other factors associated with virulence. The aim of this study was to investigate the prevalence of E. faecalis strains in secondary endodontic/ persistent using endodontic infection by culture and PCR technqiues; and to investigate for the presence of virulence factor genes of gelatinase (gelE), cytolysin activator (Cyla), surface adhesion of Enterococcus (ESP) and collagen adhesin of Enterococcus (ACE). Material and methods: Microbial samples were obtained from 12 teeth with secondary/ persistent endodontic infection showing apical periodontitis. Culture techniques were used including serial dilution, plating, incubation, and biochemical identification. For PCR detection, samples were analyzed using a species-specific primer of the 16S rDNA and the downstream intergenic spacer region. Results: Culture and PCR detected the test species in 3/12 (25%) and 5/12 (41.6%) of teeth,respectively. A total of 38 Enterococcus faecalis strains were isolated and submitted to the virulence factor genes analysis. PCR products consistent with genes encoding surface adhesion (ESP), gelatinase (gelE) and collagen binding antigen (ACE) were found in 26/38 (68%), 31/38 (81%) and 38/38 (100%) of the isolates. The Cytolysin activator (Cyla) gene was not recovered from E. faecalis isolates. Conclusions: In conclusion, the present study revealed by culture and molecular methods revealed a high prevalence of E. faecalis in teeth with secondary/ persistent endodontic infection. Moreover, of a clinical relevance, we found different E. faecalis strains carrying different virulence determinants.

Objetivos: O objetivo deste estudo foi investigar a prevalência de cepas de E. faecalis em canais com infecções endodônticas secundárias/persistentes por meio de cultura e PCR, além de analisar a presença de fatores de virulência genéticos como: gelatinase (gelE), ativador de citolisina (Cyla), adesina de superfície (ESP) e adesina de colágeno (ACE). Material e métodos: Foram coletadas amostras de 12 canais radiculares com infecção endodôntica secundária/persistente e presença de lesão periapical. Para a cultura microbiológica foi realizada diluição em série, incubação e identificação bioquímica dos microrganismos, enquanto que no PCR as amostras foram analisadas através de primers específicos 16S rDNA. Os casos com presença de Enterococcus faecalis foram selecionadas para realização de análise quanto aos fatores de virulência: gelE, Cyla, ESP e ACE. Resultados: Enterococcus faecalis foi detectado através de cultura e PCR em 3/12 (25%) e 5/12 (41,6%) dos casos, respectivamente. No total, foram isoladas 38 amostras com presença de E. faecalis. Os produtos de PCR consistentes com os genes ESP, gelE e ACE foram encontrados em 26 /38 (68%), 31 /38 (81%) e 38/38 (100%) dos isolados. Cyla não foi recuperado a partir de E. faecalis em nenhum dos isolados. Conclusões: O presente estudo revelou alta prevalência de E. faecalis em dentes com infecção endodôntica secundária/ persistente. Estes microrganismos apresentaram elevado índice de diferentes fatores de virulência.

Culture and molecular detection of Enterococcus faecalis from patients with failure endodontic treatment and antimicrobial susceptibility of clinical isolates / Cultura e detecção molecular de Enterococcus faecalis de pacientes com insucesso no tratamento endodôntico e suscetibilidade antimicrobiana dos isolados clínicos

Objective: The aim of this study was to evaluate the minimal inhibitory concentrations (MIC) of different antibiotic agents against to the most prevalent microorganism found in root-filled canals by culture and molecular approaches. Material and Methods: The microbial samples were taken either from thirty root-filled canals after removal of gutta-percha. Culture methods and 16s rDNA assay were used to identify the E faecails present in the samples. The antimicrobial susceptibilities of the isolates of E faecalis were determined by MIC values using the E test System and interpreted according to the Clinical and Laboratory Standards Institute guidelines. The following antibiotics were used: benzylpenicillin, amoxicillin, amoxicillin-clavulanic acid, erythromycin, azithromycin, vancomycin, chloramphenicol, tetracycline, doxycycline, ciprofloxacin, rifampicin and moxifloxacin. Results: E faecalis were isolated (7/30) and detected (13/30) by culture and PCR assay, respectively. All tested E faecalis (n = 12) were highly sensitive to amoxicillin, moxifloxacin, vancomycin, benzylpenicillin and amoxicillin-clavulanic acid. Isolated E faecalis strains were resistant to some antibiotics such as rifampicin (4/12), tetracycline (2/12), doxycycline (1/12), erythromycin (3/12) and azythromycin (8/12). Conclusion: Amoxicillin, amoxicillin-clavulanic acid, benzylpenicillin, vancomycin and moxifloxacin were the most active antibiotics, in vitro, against E faecalis clinical strains, with all the isolates being susceptible Azithromycin and erythromycin were least effective, with none percentage of isolates being susceptible, during laboratory testing. Moreover, E faecalis were identified more frequently by PCR assay than by culture technique.

Objetivo: O objetivo deste estudo foi avaliar as concentrações inibitórias mínimas (CIM) de diferentes antibióticos contra micro-organismos mais prevalentes em canais radiculares pelos métodos moleculares e de cultura. Material e Métodos: As amostras microbianas foram obtidas de trinta canais radiculares após a remoção da gutapercha. Os métodos de cultura e ensaio 16s rDNA foram utilizados para identificar E. faecalis presente nas amostras. As susceptibilidades antimicrobianas dos isolados de E. faecalis foram determinadas pelos valores de CIM utilizando o sistema E teste e interpretados de acordo com as diretrizes CLSI(Clinical and Laboratory Standards Institute). Foram utilizados os seguintes antibióticos: benzilpenicilina, amoxicilina, amoxicilina com ácido clavulânico, eritromicina, azitromicina, vancomicina, cloranfenicol, tetraciclina, doxiciclina, ciprofloxacina, moxifloxacina e rifampicina. Resultados: E. faecalis foram isolados (7/30) e detectados (13/30) por cultura e pelo método PCR, respectivamente. Todos E. faecalis (n = 12) foram altamente sensíveis à amoxicilina,moxifloxacina,vancomicina, benzilpenicilina e amoxicilina com ácido clavulânico. Cepas isoladas de E. faecalis foram resistentes a alguns antibióticos como a rifampicina (4/12), tetraciclina (2/12), doxiciclina (1/12), eritromicina (3/12) e azitromicina (8/12). Conclusão: Amoxicilina, amoxicilina com ácido clavulânico, benzilpenicilina, vancomicina e moxifloxacina foram os antibióticos mais ativos, in vitro, contra cepas clínicas de E. faecalis, com todos os isolados sendo suscetíveis. Azitromicina e eritromicina foram menos eficazes, com nenhuma porcentagem de isolados suscetível durante os testes laboratoriais. E ainda, E. faecalis foram identificados mais frequentemente pela técnica PCR do que pela técnica de cultura.

Effect of root perforations on the bond strength of fiberglass post using different adhesive systems and resin cement / Efeito das perfurações radiculares na resistência de união de pinos de fibra de vidro utilizando diferentes sistemas adesivos e cimento resino

Objective: This study evaluated the effect of root perforations on the bond strength of fiberglass posts cemented to the root canal with two adhesive systems and resin cement. Material and Methods: Forty single-rooted human teeth received endodontic treatment and were prepared for the cementation of fiberglass posts (Exacto Mini, Angelus). The teeth were divided into four experimental groups (n = 10) according to the root condition (with or without perforation) and the adhesive system used: G1: without perforation + Adper Single Bond 2 (3M ESPE), G2: without perforation + Clearfil SE Bond (Kuraray), G3: with perforation + Adper Single Bond 2, G4: with perforation + Clearfil SE Bond. The perforation was executed on the root surface with a diamond bur and sealed with white mineral trioxide aggregate (MTA). The specimens were sectioned and a push-out test was carried out (1 mm/min speed and 50 kgf). The data were statistically analyzed by ANOVA and Tukey Test (5%). Results: Adper Single Bond 2 promoted the greatest values of bond strength to the roots without root perforation. The presence of root perforation led to the reduction in bond strength values regardless of the bonding system used (p < 0.05). Conclusion: The root perforations caused a direct effect on the bond strength of the fiberglass posts cemented by reducing the bond strength values to the root dentin regardless of the adhesive system used.

Objetivo: O objetivo deste estudo foi avaliar o efeito das perfurações radiculares na resistência de união de pinos de fibra de vidro cimentados com dois sistemas adesivos e um cimento resinoso. Material e Métodos: Quarenta dentes humanos unirradiculares receberam tratamento endodôntico e foram preparados para cimentação de pinos de fibra de vidro (Exacto Mini, Angelus). Os dentes foram divididos em quatro grupos experimentais (n = 10) de acordo com a condição radicular (com ou sem perfuração) e o sistema adesivo utilizado: G1: sem perfuração + Adper™ Single Bond 2; G2: sem perfuração + Clearfil SE Bond; G3: com perfuração + Adper™ Single Bond 2; G4: com perfuração + Clearfil SE Bond. A perfuração foi realizada na superfície radicular com uma ponta diamantada e selada com agregado de trióxido mineral branco (MTA). Os espécimes foram seccionados para realização do teste de extrusão por cisalhamento (Push-out) com velocidade de 1 mm/ min e célula de carga de 50 Kgf. Os dados obtidos foram submetidos à Análise de Variância (ANOVA) e Teste de Tukey a 5%. Resultados: O sistema adesivo Adper Single Bond 2 promoveu os maiores valores de resistência de união nas raízes sem perfuração radicular. A presença de perfuração promoveu redução nos valores de resistência de união, independentemente do sistema adesivo utilizado (p < 0,05). Conclusão: As perfurações radiculares causaram efeito direto sobre a resistência de união dos pinos de fibra de vidro, promovendo redução nos valores da resistência de união independentemente do tipo de sistema adesivo utilizado.

Influence of the apical enlargement size on the endotoxin level reduction of dental root canals

Gram-negative bacteria play an essential role in endodontic infections because they have virulence factors such as endotoxin. Due to its potential cytotoxic activity, special attention has been given to the removal/neutralization of this endotoxin in the root canal system. OBJECTIVE: The aim of this study was to evaluate the influence of the apical enlargement size (AES) by using rotary instruments on the endotoxin level reduction of dental root canals. MATERIAL AND METHODS: Forty root canals of the mandibular premolar teeth were used. Escherichia coli endotoxin (055: B55) was inoculated into thirty root canals. Ten teeth served as the negative control group. After the incubation period, the first endotoxin samples were collected from the root canals with a sterile/apyrogenic paper point for the analysis of the endotoxin units (EU/mL) present before instrumentation (S1). Specimen instrumentation was performed with the Mtwo® rotary system in the sequence 10/.04, 15/.05, 20/.06, 25/.06, 30/.05, 35/.04 and 40/.04. To monitor the effectiveness of increasing apical enlargement on endotoxin removal, the second endotoxin samples were collected from all the root canals after instrumentation with the following instruments: #25/.06- (S2); #30/.05- (S3); # 35/.04- (S4); and #40/.04- (S5). Limulus amebocyte lysate (LAL) was used to quantify the levels of endotoxin. The results were statistically compared by using repeated measures of ANOVA with post hoc Tukey testing. RESULTS: Increasing levels of endotoxin removal was achieved by large sized apical enlargement: S2 (AES #25/.06)- 89.2%, S3 (AES #30/.05)- 95.9%, S4 (AES #35/.04)- 97.8% and S5 (AES #40/.04)- 98.2%. Substantial reduction of endotoxin content was obtained in S4 and S5 compared to S2 (p<0.05), however, the root canal preparation was not able to eliminate the endotoxin. CONCLUSIONS: Under the conditions of this study, it was concluded that the reduction of endotoxin levels of the dental root canals could be predicted by increasing the apical enlargement size.

Morfologia interna de pré-molares inferiores: estudo in vitro / Root-canal morphology of mandibular premolars: an in vitro study

O objetivo deste trabalho, in vitro, foi comparar a detecção de canais em 100 pré-molares inferiores humanos por método radiográfico, exame a olho nu, com auxílio de microscópio operatório clínico (MOC), após diafanização, e também analisar a frequência de multiplicidade anatômica dos canais observados. Não houve diferença significativa entre os meios de detecção (Kruskal-Wallis). A maior incidência foi de canais únicos, sendo 52% nos primeiros e 86% nos segundos. Observou-se a presença de três canais em 6% dos primeiros pré-molares. Houve diferença significativa (Mann-Whitney - p<0,0001) na presença de múltiplos canais nos primeiros pré-molares em relação aos segundos.