Root canal contamination or exposure to lipopolysaccharide differentially modulate prostaglandin E 2 and leukotriene B 4 signaling in apical periodontitis

Abstract Purpose To evaluate the kinetics of apical periodontitis development in vivo , induced either by contamination of the root canals by microorganisms from the oral cavity or by inoculation of bacterial lipopolysaccharide (LPS) and the regulation of major enzymes and receptors involved in the arachidonic acid metabolism. Methodology Apical periodontitis was induced in C57BL6 mice (n=96), by root canal exposure to oral cavity (n=48 teeth) or inoculation of LPS (10 µL of a suspension of 0.1 µg/µL) from E. coli into the root canals (n= 48 teeth). Healthy teeth were used as control (n=48 teeth). After 7, 14, 21 and 28 days the animals were euthanized and tissues removed for histopathological and qRT-PCR analyses. Histological analysis data were analyzed using two-way ANOVA followed by Sidak's test, and qRT-PCR data using two-way ANOVA followed by Tukey's test (α=0.05). Results Contamination by microorganisms led to the development of apical periodontitis, characterized by the recruitment of inflammatory cells and bone tissue resorption, whereas inoculation of LPS induced inflammatory cells recruitment without bone resorption. Both stimuli induced mRNA expression for cyclooxygenase-2 and 5-lipoxygenase enzymes. Expression of prostaglandin E 2 and leukotriene B 4 cell surface receptors were more stimulated by LPS. Regarding nuclear peroxisome proliferator-activated receptors (PPAR), oral contamination induced the synthesis of mRNA for PPARδ, differently from inoculation of LPS, that induced PPARα and PPARγ expression. Conclusions Contamination of the root canals by microorganisms from oral cavity induced the development of apical periodontitis differently than by inoculation with LPS, characterized by less bone loss than the first model. Regardless of the model used, it was found a local increase in the synthesis of mRNA for the enzymes 5-lipoxygenase and cyclooxygenase-2 of the arachidonic acid metabolism, as well as in the surface and nuclear receptors for the lipid mediators prostaglandin E2 and leukotriene B4.

Molecular Typing of Enterococcus faecalis from Persistent Endodontic Infections / Tipificación Molecular de Enterococcus faecalis Provenientes de Infecciones Endodónticas Persistentes

ABSTRACT: Molecular techniques that provide valuable information about the epidemiology of oral strains. The purpose of this study was to determine the genetic relatedness of 83 Enterococcus faecalis strains isolated from treated root canals. These strains were obtained from patients who were treated for persistent endodontic infections. E. faecalis isolates were molecular typed by Pulsed Field Gel Electrophoresis using Smal. Ten clonal groups and 13 pulse types with 38.7 % similarity for the less related strains were identified. Genetic heterogeneity among strains from different patients and a high level of genetic homogeneity among intrapatient strains were observed. Therefore, restriction endonuclease fingerprinting of genomic DNA from E. faecalis strains confirmed the polyclonality of the isolates obtained from the root canals of patients diagnosed with persistent endodontic infections, compared with other reports. These results provide additional data for a better understanding of the epidemiological aspects of root canal infections by E. faecalis.

RESUMEN: Las técnicas moleculares proporcionan información valiosa sobre la epidemiología de aislados orales. El propósito de este estudio fue determinar la relación genética de 83 cepas de Enterococcus faecalis aisladas de conductos radiculares tratados. Estas cepas se obtuvieron de pacientes que fueron tratados por infecciones endodónticas persistentes. Los aislados de E. faecalis se tipificaron molecularmente por electroforesis en gel de campo pulsado usando Smal. Se identificaron diez grupos clonales y 13 pulsotipos con un 38,7 % de similitud para las cepas menos relacionadas. Se observó heterogeneidad genética entre las cepas de diferentes pacientes y un alto nivel de homogeneidad genética entre las cepas intrapacientes. Por lo tanto, la toma de huellas dactilares a traves de restricción de ADN genómico de cepas de E. faecalis confirmó la policlonalidad de los aislados obtenidos de los conductos radiculares de pacientes diagnosticados con infecciones endodónticas persistentes, en comparación con otros informes. Estos resultados proporcionan datos adicionales para una mejor comprensión de los aspectos epidemiológicos de las infecciones del conducto radicular por E. faecalis.

Dendritic cells and their relation to apical peridontitis

Abstract: The purpose of this manuscript was to re-discuss apical periodontitis, apical biofilm, and its possible relationship with dendritic cells (DC). DCs are potent regulators of the immune system and their function is divided into three categories that involve the presentation of antigens: the presentation of antigens and activation of T cells; a not well established category suggested that DCs induce and maintain immunological tolerance; and the maintenance of the immune memory in conjunction with B cells. DCs in periapical inflammatory lesions are composed of at least two subpopulations that can be distinguished on the basis of ultrastructure and phenotype. These populations might differ in lineage, state of maturation, differentiation, activation, and/or function. The authors hereby analyzed the root apexes of teeth under SEM, after performing apicoectomy due to the failure of conventional endodontic treatment. Microbial biofilm with multispecies and areas of resorption with the presence of Howship lacunae, and images suggestive of denditric cells could be observed. The presence of DCs in periapical lesion could be an indication of the severity of the lesion, with a constant presence of antigen in the periradicular region.

Etiologic role of root canal infection in apical periodontitis and its relationship with clinical symptomatology

Abstract: Evidence shows the polymicrobial etiology of endodontic infections, in which bacteria and their products are the main agents for the development, progression, and dissemination of apical periodontitis. Microbial factors in necrotic root canals (e.g., endotoxin) may spread into apical tissue, evoking and supporting a chronic inflammatory load. Thus, apical periodontitis is the result of the complex interplay between microbial factors and host defense against invasion of periradicular tissues. This review of the literature aims to discuss the complex network between endodontic infectious content and host immune response in apical periodontitis. A better understanding of the relationship of microbial factors with clinical symptomatology is important to establish appropriate therapeutic procedures for a more predictable outcome of endodontic treatment.

Evaluación de Lesiones Periapicales en Pacientes Derivados a Cirugía Periapical Mediante Tomografía Computarizada de Haz Cónico / Evaluation of Periapical Lesions by Cone Beam Computed Tomography in Patients Referred for Apical Surgery

El uso de la tomografía computarizada de haz cónico (CBCT) en endodoncia ha ido en aumento, justificando su uso en casos más complejos, como cirugías periapicales. El objetivo fue evaluar las características imagenológicas encontradas en un grupo de pacientes derivados a cirugía periapical, mediante el uso de CBCT. Se realizó un estudio observacional descriptivo, en un grupo de pacientes, derivados a cirugía periapical, a los cuales se realizó un examen de CBCT, evaluación clínica y radiografía periapical. Un total de 18 pacientes fueron examinados (6 hombres y 12 mujeres), cuyas edades estaban entre los 19 y 64 años de edad. El diámetro mayor de las lesiones varió entre 6 mm a 16 mm. El uso de CBCT en cirugías periapicales entrega información más completa al cirujano, ya que permite mayor precisión al realizar el acceso quirúrgico y detecta un mayor número de lesiones periapicales que con la radiografía periapical, logrando en casos complejos un mejor diagnóstico y planificación del tratamiento.

The use of cone beam computed tomography (CBCT) in endodontics has increased, justifying its use in more complex cases, such as apical surgery. The aim was to evaluate the radiologic characteristics found in a group of patients referred to apical surgery, using CBCT. A descriptive study was conducted in a group of patients referred for apical surgery. In these patients, a clinical examination, a conventional radiographic evaluation and CBCT were performed. A total of 18 patients were examined (6 men and 12 women), ages were between 19 and 64 years old. The major diameter of the lesions ranged from 6 mm to 16 mm. The use of CBCT in apical surgery provides more complete information to the surgeon, allowing greater precision when performing surgical access and detects a greater number of periapical lesions than with conventional radiography. In complex cases is possible obtain better diagnosis and treatment planning.

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.

Susceptibilidad antimicrobiana de microorganismos anaerobios aislados de infecciones endodónticas primarias a amoxicilina y metronidazol y su asociación con los parámetros clínicos: serie de casos / Antimicrobial susceptibility of anaerobic microorganisms isolated from primary endodontic infections to amoxicillin and metronidazole and its association with clinical parameters: case series

El objetivo de este estudio es describir la composición de la microbiota anaerobia estricta/aerotolerante en infecciones endodónticas primarias, su susceptibilidad antimicrobiana, y la asociación con los parámetros clínicos. Se tomaron muestras de siete pacientes con necrosis pulpar sintomática o asintomática. Se utilizaron técnicas para la conservación, cultivo, incubación e identificación de anaerobios estrictos/aerotolerantes. Para determinar la susceptibilidad antimicrobiana a amoxicilina y metronidazol, se utilizó el método de dilución en agar. Se aislaron un total de 32 cepas, 20 (62,5 %) fueron anaerobios estrictos/aerotolerantes, y 8 (25 %) anaerobios facultativos. El microorganismo anaerobio estricto/aerotolerante más frecuente fue Fusobacterium nucleatum, se aisló en tres casos, todos relacionados con algún tipo de dolor, y en dos casos estuvo relacionado con Prevotella spp. Se encontró una colonia de F. nucleatum resistente a amoxicilina y con producción de ß-lactamasa, y otra de F. nucleatum resistente a metronidazol. Una colonia de P. propionicum/avidus presentó resistencia intermedia a amoxicilina y con producción de ß-lactamasa. Se encontró la presencia de bacterias anaerobias estrictas/aerotolerantes en los pacientes con infecciones endodónticas primarias. Existen algunos microrganismos relacionados con algún tipo de dolor, como F. nucleatum y P. micra. Los hallazgos muestran presencia de F. nucleatum resistentes a los antimicrobianos evaluados.

The objective of this study is to describe the composition of the strict / aerotolerant anaerobic microbiota in primary endodontic infections, antimicrobial susceptibility, and the association with clinical variables. Samples were taken from seven patients with symptomatic or asymptomatic pulp necrosis. conservation techniques, cultivation, incubation and identification of strict / aerotolerant anaerobes. We used the agar dilution method to determine the antimicrobial susceptibility to amoxicillin and metronidazole. A total of 32 strains, 20 (62.5 %) were isolated were strict / aerotolerant anaerobes, and 8 (25 %) facultative anaerobe organisms. The strict anaerobe / more Fusobacterium nucleatum was frequently aerotolerant, it was isolated in three cases, all related to some type of pain, and in two cases it was related to Prevotella spp. a colony of F. nucleatum resistant to amoxicillin and ß-lactamase production was found, and another F. nucleatum resistant to metronidazole. A colony of P. propionicum / avidus presented intermediate amoxicillin and ß-lactamase producing resistance. Conclusions: the presence of strict anaerobic bacteria / aerotolerant in patients with primary endodontic infections was found. There is some related pain, as F. nucleatum and P. micra microorganisms. The findings show the presence of F. nucleatum resistant to the antimicrobial organisms evaluated.

Aspergillus in endodontic infection near the maxillary sinus / Aspergillus em infecções endodônticas próximas ao seio maxilar

ABSTRACT INTRODUCTION: Diseases of the maxillary sinus have been associated with dental roots near the maxillary sinus that have undergone endodontic treatment. OBJECTIVE: To investigate the presence of filamentous fungi in patients with dental roots near the maxillary sinus who had apical periodontitis treated endodontically, and to alert practitioners that this could be a possible avenue of contamination of the sinus in patients who develop maxillary sinus infection. METHODS: Cross-sectional study in 60 palatal roots of the first maxillary molars near the maxillary sinus, that underwent endodontic treatment for apical periodontitis. After removal of the filling material, dentin shavings were collected and placed in test tubes containing Sabouraud dextrose agar and chloramphenicol. The phenotype was determined by macroscopic and microscopic examination of the colonies. For polymerase chain reaction, the primers ITS-5 and ITS-4 were used. The sequences obtained were compared with those deposited at GenBank using the Basic Local Alignment Search Tool program. RESULTS: Filamentous fungi were isolated from 6 of 60 canals (10%):Aspergillus niger (6.7%), Aspergillus versicolor (1.6%), and Aspergillus fumigatus(1.6%). CONCLUSION: Root canals near the maxillary sinus with endodontic treatment and apical periodontitis may exhibit positive cultures for filamentous fungi. Interested professionals should be alert, because these microorganisms have pathogenic characteristics that can cause disease of odontogenic origin in the maxillary sinus.

RESUMO Introdução: Doenças do seio maxilar têm sido associadas à raízes com tratamento endodôntico próximas ao seio maxilar. Objetivo: Investigar a presença de fungos filamentosos em raízes com tratamento endodôntico e lesão periapical, próximas ao seio maxilar, alertando para uma possível contaminação do seio maxilar por via odontogênica. Método: Estudo transversal em sessenta raízes palatinas de primeiros molares superiores próximas ao seio maxilar, com tratamento endodôntico e lesão periapical. Após remoção do material obturador, raspas de dentina foram coletadas e inseridas em tubos de ensaio contendo Agar Sabouraud Dextrose e Clorafenicol. O fenótipo foi determinado pela análise macroscópica e microscópica das colônias. Para o PCR utilizou-se iniciadores ITS-5 e ITS-4. As sequencias obtidas foram comparadas as disponíveis no GenBank utilizando Basic Local Alignment Search Tool. Resultados: Fungos filamentosos foram isolados de 6 dos 60 canais (10%):Aspergillus niger (6,7%), Aspergillus versicolor (1,6%) e Aspergillus fumigatus(1,6%). Conclusão: Raízes próximas ao seio maxilar com tratamento endodôntico e lesão periapical, podem apresentar cultura positiva para fungos filamentosos. Profissionais afins devem estar alerta, pois este micro-organismo possuem características de patogenicidade podendo causar doenças no seio maxilar de origem odontogênica.

Prevalence of Treponemaspp. in endodontic retreatment-resistant periapical lesions

This study investigated the presence of the Treponema species in longstanding endodontic retreatment-resistant lesions of teeth with apical periodontitis, the association of this species with clinical/radiographic features, and the association among the different target species. Microbial samples of apical lesions were collected from twenty-five adult patients referred to endodontic surgery after unsuccessful root canal retreatment. Nested-PCR and conventional PCR were used for Treponema detection. Twenty-three periradicular tissue samples showed detectable levels of bacterial DNA. Treponema species were detected in 28% (7/25) of the cases. The most frequently detected species were T. socranskii (6/25), followed by T. maltophilum (3/25), T. amylovorum (3/25), T. lecithinolyticum(3/25), T. denticola (3/25), T. pectinovorum (2/25) and T. medium(2/25). T. vicentii was not detected in any sample. Positive statistical association was found between T. socranskiiand T. denticola,and between T. maltophilumand T. lecithinolyticum. No association was detected between the presence of any target microorganism and the clinical or radiographic features. Treponemaspp.are present, in a low percentage, in longstanding apical lesions from teeth with endodontic retreatment failure.

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 ...

Diversidade microbiana em infecções endodônticas primárias associadas ao traumatismo dentário / Microbial diversity in primary root canal infections associated with dental trauma

O presente trabalho tem por objetivo investigar a microbiota de canais radiculares, buscando a identificação e a quantificação destes microrganismos. Foram selecionados 31 dentes com infecção primária devido a traumatismo dentário. As amostras microbiológicas foram coletadas dos canais com o auxílio de limas tipo Hedströen e cones de papel absorvente estéril. A técnica do Checkerboard DNA-DNA hybridization foi utilizada para detecção de até 38 espécies bacterianas em cada amostra, utilizando sondas de DNA específicas. Os dados microbiológicos foram expressos em percentagem média (prevalência), nível médio (contagem) e proporção de cada espécie em cada amostra. Os testes t independente e de correlação de Pearson foram usados para correlacionar as bactérias testadas com os tipos de trauma (p≤ 0,05). Foi encontrada uma média de 13,74 espécies por amostra. As espécies mais prevalentes foram P. melaninogenica (84%), E. faecalis (77%), C. gracilis (71%) e F. nucleatum sp. vicentii (71%). Algumas espécies demonstraram baixa prevalência, sendo elas A. odontolyticus (26%), P. acnes (26%), E. corrodens (23%), A. israelii (16%), A. gerencseriae (16%), P. endodontalis (16%) e A. naeslundii (13%). As espécies F. nucleatum sp. vicentii, P. nigrescens, T. denticola, C. gingivalis, C. rectus e P. gingivalis apresentaram níveis médios significativamente maiores entre os casos de trauma dentário e trauma de tecidos de suporte (P < 0,05). As bactérias T. denticola, C. gingivalis e P. gingivalis também apresentaram proporções significativamente mais elevados no casos de trauma de tecidos de suporte (p>0,05). Baseado nos resultados obtidos é possível concluir que o perfil da microbiota presente em dentes com periodontite apical primária causada por traumatismos dentários pode variar de acordo com a ocorrência de dano aos tecidos de suporte.

This study aims to investigate the microbiota of root canals, seeking to identify and quantify these microorganisms. Thirty one teeth with related primary infection due to dental trauma were selected. Microbiological samples were collected from the root canal using Hedströen files and sterile absorbent paper points. The checkerboard DNA-DNA hybridization molecular technique was used to detect up to 38 bacterial species in each sample using specific DNA probes. Microbiological data were expressed as mean percentage (prevalence), mean level (score) and the proportion of each species in each sample. The independent and Pearson correlation tests were used to correlate the bacterias tested with the types of trauma (p ≤ 0.05). An average of 13.74 species per sample was found. The most prevalent species were P. melaninogenica (84%), E. faecalis (77%), C. gracilis (71%) and F. nucleatum sp. vicentii (71%). The species that showed low prevalence were A. odontolyticus (26%), P. acnes (26%), E. corrodens (23%), A. israelii (16%), A. gerencseriae (16%), P. endodontalis (16%) and A. naeslundii (13%). The species F. nucleatum sp. vicentii, P. nigrescens, T. denticola, C. gingivalis, C. rectus and P. gingivalis showed significantly higher mean levels between cases of trauma to the supporting tissues and cases of dental trauma (P <0.05). T. denticola, P. gingivalis and C. gingivalis also showed significant higher ratios in the trauma to the supporting tissues cases (p> 0.05). Based on the obtained results, it can be concluded that the bacterial profile of pulpal necrosis caused by traumactic injuries may vary depending on the occurrence of damage to the supporting tissues.

A ação do hidróxido de cálcio frente ao enterococcus faecalis nos casos de periodontite apical secundária: [revisão] / The action of calcium hydroxide against enterococcus faecalis in cases of secondary apical periodontitis: [review]

Introdução: a infecção da polpa e dos tecidos periapicais tem a sua etiologia discutida há anos. A periodontite apical é caracterizada por ser de origem polimicrobiana, sendo o Enterococcus faecalis o microorganismo mais comumente encontrado. Em situações clínicas, o objetivo do tratamento endodôntico é eliminar micro-organismos do sistema de canais radiculares. As medicações intracanal são um importante passo no tratamento e devem ser efetivas frente aos micro-organismos que resistem ao preparo do canal radicular. Dentre as medicações empregadas, o hidróxido de cálcio é utilizado rotineiramente como medicação intracanal. Sua ação se deve ao fato de estabelecer um pH altamente alcalino dentro do canal radicular, 12,5 aproximadamente, no qual a maioria dos microorganismos não consegue sobreviver. Objetivo: realizar uma revisão de literatura sobre a relação do Enterococcus faecalis no insucesso endodôntico e a efetividade do hidróxido de cálcio nesta situação clínica. Conclusão: a ação do hidróxido de cálcio frente ao Enterococcus faecalis é limitada.

Introduction: Pulp and periapical tissue infection etiology has been discussed for many years. Apical periodontitis is characterized by multimicrobial flora origin, in which Enterococcus faecalis is the microorganism more frequently found. In clinical situations, the aim of endodontic treatment is to remove microorganisms of the system of root canals. Intra canal medications are an important step in the treatment and they must be effective in microorganisms that resist the preparation of the root canal. Among all used medications, the calcium hydroxide is frequently used. It acts establishing a highly alkaline pH inside the root canal, 12.5 approximately, in which most of the microorganisms do not manage to survive.Aim: to make a review of the literature about the relationship on the Enterococcus faecalis on endodontic failure and calcium hydroxide effectiveness in this clinical situation. Conclusion: Calcium hydroxide has limited action against Enterococcus faecalis.

Analysis of Enterococcus faecalis in samples from Turkish patients with primary endodontic infections and failed endodontic treatment by real-time PCR SYBR green method

OBJECTIVE: The aims of this study were to investigate the presence of Enterococcus faecalis in primary endodontic infections and failed endodontic treatments using real-time PCR and to determine the statistical importance of the presence of E. faecalis in a Turkish population with endodontic infections. MATERIAL AND METHODS: E. faecalis was investigated from 79 microbial samples collected from patients who were treated at the Endodontic Clinic of the Dental School of Atatürk University (Erzurum, Turkey). Microbial samples were taken from 43 patients (Group 1) with failed endodontic treatments and 36 patients (Group 2) with chronic apical periodontitis (primary endodontic infections). DNA was extracted from the samples by using a QIAamp® DNA mini-kit and analyzed with real-time PCR SYBR Green. RESULTS: E. faecalis was detected in 41 out of 79 patients, suggesting that it exists in not less than 61 percent of all endodontic infections when the proportion test (z= -1.645,

Análise comparativa dos níveis de proteína C-reativa altamente sensível entre indivíduos portadores e não portadores de lesão periapical crônica / Comparative analysis of C-reactive protein in patients with and without chronic apical periodontitis

As doenças bucais inflamatórias crônicas, como a doença periodontal, estão relacionadas com a etiopatogênese das doenças arteriais coronarianas, causando danos endoteliais e facilitando a formação das placas ateromatosas. As doenças inflamatórias do periápice, assim como a doença periodontal, são doenças bacterianas que ativam a produção localizada de citocinas e outros mediadores próinflamatórios, como a proteína C-reativa (PCR). Essa proteína tem sido utilizada como um marcador sistêmico da inflamação, infecção e da lesão celular. Suas concentrações podem detectar doenças ocultas no organismo e monitorar a resposta ao tratamento de certos processos inflamatórios e infecciosos. O objetivo desse trabalho foi avaliar se as lesões periapicais crônicas podem ativar a resposta inflamatória, gerando repercussões sistêmicas e determinar se o método da PCR altamente sensível (PCR-as) por imunoturbidimetria pode ser utilizado para o diagnóstico e monitoramento do tratamento endodôntico destas lesões. Assim, comparou-se os níveis plasmáticos da PCR entre 13 indivíduos portadores e 13 indivíduos não portadores de lesão periapical crônica. Foram comparados também os níveis da PCR dos indivíduos portadores de lesão periapical crônica antes e após o tratamento do dente em questão. Não foi possível observar diferenças estatisticamente significantes entre os valores da PCR dos pacientes portadores de lesão periapical crônica antes e após os tratamentos (p=0,9203 com o teste t para amostras emparelhadas e p=0,94427 com o teste Wilcoxon), nem mesmo quando comparou-se os pacientes com lesão periapical crônica com os pacientes controles (p=0,1012 com o teste t para amostras independentes e p=0,1585 com o teste Mann Whitney). Pode-se concluir, com base na metodologia adotada, que as lesões periapicais crônicas não são capazes de induzir uma resposta inflamatória de repercussão sistêmica e o método da PCR-as por imunoturbidimetria não pode ser utilizado para o diagnóstico...

Inflammatory effects from periodontal disease can cause oral bacterial by products to enter the bloodstream. These effects may cause blood clots that contribute to a coronary heart disease risk factor. Chronic apical periodontitis are also bacterial diseases that stimulate the production of cytokines and other cell-mediated inflammatory factors such as C-reactive protein (CRP). CRP is one of the acute phase proteins that increase during systemic inflammation. Its been suggested that testing CRP levels in the blood may be an additional way to assess cardiovascular disease risk. The aim of this study was to evaluate if chronic apical periodontitis can ativate inflammatory response leading to systemic effects and to determine if a highly sensitive CRP (hs-CRP) assay is available to diagnose and track the endodontic treatment of these lesions. Plasma levels of hs-CRP were compared in blood of 13 individuals with chronic apical periodontitis and 13 healthy controls. CRP levels were also compared in the individuals with chronic apical periodontitis before and after treatment of the tooth. There was no statistical association among CRP levels of individual with or without chronic apical periodontitis (p=0,1012 for t test and p=0,1585 for Mann Whitney test). There was no statistical association among CRP levels of individual with chronic apical periodontitis before and after dental treatments (p=0,9203 for t test and p=0,94427 for Wilcoxon test). In conclusion, these results suggest that chronic apical periodontitis can not ativate inflammatory response leading to systemic effects and even a highly sensitive CRP (hs-CRP) assay is not available to diagnose and track the endodontic treatment of these lesions.

Microbial distribution in the root canal system after periapical lesion induction using different methods

The aim of this study was to evaluate the microbial distribution in the root canal system after periapical lesion induction in dogs' teeth using different methods. Fifty-two root canals were assigned to 4 groups (n=13). Groups I and II: root canals were exposed to the oral cavity for 180 days; groups III and IV: root canals were exposed for 7 days and then the coronal openings were sealed for 53 days. The root apices of groups I and III were perforated, while those of groups II and IV remained intact. After the experimental periods, the animals were euthanized and the anatomic pieces containing the roots were processed and stained with the Brown & Brenn method to assess the presence and distribution of microorganisms. The incidence of microorganisms at different sites of the roots and periapical lesions was analyzed statistically by the chi-square test at 5 percent significance level. All groups presented microorganisms in the entire root canal system. A larger number of microorganisms was observed on the root canal walls, apical delta and dentinal tubules (p<0.05), followed by cementum and cemental resorption areas. In spite of the different periods of exposure to the oral environment, the methods used for induction of periapical periodontitis yielded similar distribution of microorganisms in the root canal system.

O objetivo deste estudo foi avaliar a distribuição microbiana no sistema de canais radiculares após indução de lesões periapicais em dentes de cães por diferentes métodos. Cinqüenta e dois canais radiculares foram divididos em 4 grupos (n=13). Grupos I e II: canais radiculares foram expostos por 180 dias; grupos III e IV: canais radiculares foram expostos por 7 dias e então as aberturas coronárias foram seladas por 53 dias. Os ápices radiculares dos grupos I e III foram arrombados, enquanto os dos grupos II e IV foram mantidos intactos. Após os períodos experimentais, os animais foram mortos e as peças foram processadas e coradas pelo método de Brown e Brenn para avaliação da presença ou ausência e distribuição dos microrganismos. A incidência de microrganismos nas diferentes regiões das raízes e lesões periapicais foi analisada estatisticamente pelo Teste Qui-Quadrado em nível de 5 por cento de significância. Todos os grupos apresentaram microrganismos em todo o sistema de canais radiculares. Um maior número de microrganismos foi observado nas paredes do canal radicular, delta apical e túbulos dentinários, seguido pelo cemento e áreas de reabsorção cementária. Apesar de utilizar diferentes períodos de exposição dos canais radiculares ao meio bucal, os métodos usados para indução das lesões periapicais permitiram semelhante distribuição de microrganismos no sistema de canais radiculares (p>0,05).

Bacterial pathogenesis and mediators in apical periodontitis: [review]

Apical periodontitis is a group of inflammatory diseases caused by microorganisms (mainly bacteria) infecting the necrotic root canal system. The pathogenesis of different types of apical periodontitis and even the same type in different individuals is unlikely to follow a stereotyped fashion with regard to the involved bacterial mediators. Disease pathogenesis is rather complex and involves a multitude of bacteria- and host-related factors. This review article discusses the bacterial pathogenesis of acute and chronic apical periodontitis, with the main focus on the bacterial mediators conceivably involved in the different stages of the infectious process, including secreted products (enzymes, exotoxins, N-formyl-methionyl-leucyl-phenylalanine peptides, heat-shock proteins and metabolic end-products) and structural components (lipopolysaccharide, peptidoglycan, lipoteichoic acid, lipoproteins, fimbriae, flagella, outer membrane proteins and vesicles, DNA, and exopolysaccharides). Knowledge of the bacterial factors involved in the pathogenesis of apical periodontitis is important to the understanding of the disease process and to help establishing proper therapeutic measures to inactivate this bacterial "artillery".

Lesões perirradiculares compreendem um grupo de doenças inflamatórias causadas por microrganismos (principalmente bactérias) infectando o sistema de canais radiculares com polpa necrosada. É improvável que a patogênese dos diferentes tipos de lesão perirradicular, e até mesmo daquelas do mesmo tipo, mas em diferentes indivíduos, obedeça um padrão estereotipado com relação aos mediadores bacterianos envolvidos. A patogênese destas doenças é complexa e envolve inúmeros fatores relacionados às bactérias e ao hospedeiro. Este artigo de revisão discute a patogênese bacteriana das lesões perirradiculares agudas e crônicas, enfatizando os fatores bacterianos que estão possivelmente envolvidos nos diferentes estágios do processo infeccioso, incluindo produtos secretados (enzimas, exotoxinas, peptídeos N-formilados, proteínas de choque térmico e produtos terminais do metabolismo) e componentes estruturais (lipopolissacarídeo, peptidoglicano, ácido lipoteicóico, lipoproteínas, fímbrias, flagelos, proteínas e vesículas de membrana externa, DNA e exopolissacarídeos). O conhecimento dos fatores bacterianos envolvidos na patogênese das lesões perirradiculares é importante para o entendimento do processo patológico bem como para ajudar no estabelecimento de medidas terapêuticas adequadas para desativação desta "artilharia" bacteriana.

Clinical relevance of trans 1.4-polyisoprene aging degradation on the longevity of root canal treatment

This in vivo study investigated the time of degradation of root filling material (trans 1,4-polyisoprene) retrieved from endodontically treated teeth and correlated the occurrence of degradation with the longevity of endodontics. Thirty-six root-filled teeth with different filling times (2 to 30 years) and with and without periapical lesions were selected. All teeth presented clinical indication for root canal retreatment. The association among filling time, presence of periapical lesion and root filling material degradation was investigated. Root filling samples were retrieved from the root canals using a Hedströ m file without solvent. The trans 1,4-polyisoprene was isolated by root filling solubilization in chloroform followed by filtration and centrifugation. GPC and FT-IR were the analytical techniques utilized. Degradation of trans 1,4-polyisoprene occurred with time, as a slow process. It is an oxidative process, and production of carboxyl and hydroxyl groups in the residual polymer were observed. Statistically significant decrease of molar mass was observed after 5 (p=0.0001) and 15 (p=0.01) years in teeth with and without periapical lesion, respectively. Bacteria participated in polymer degradation. Gutta-percha aging was proven an important factor for the long-term success of endodontic treatment. The findings of the present study showed that, after 15 years, polymer weight loss may decrease the capacity of the filling mass to seal the root canal space and prevent re-infection, thus compromising significantly the longevity of root canal therapy.

Este estudo in vivo avaliou a degradação do material obturador e a influência deste fator na longevidade do tratamento endodôntico. Foram selecionados 36 pacientes (3-30 anos) com canais tratados endodonticamente, com e sem lesões periapicais, e indicação de retratamento endodôntico. Foi investigada a associação entre o tempo de tratamento, presença de lesão periapical e a degradação do material obturador. O material obturador foi removido com uma lima Hedströ em sem uso de solvente. O polímero trans 1,4- poliisopreno foi isolado do material obturador através de solubilização em clorofórmio, seguido de filtragem e centrifugação. GPC e FT-IR foram os métodos analíticos utilizados. A degradação do trans 1,4- poliisopreno foi observada com o tempo, sendo um processo lento e oxidativo, com formação de grupos carboxílicos e hidroxilas no polímero residual. Após 5 (p=0,0001) e 15 (p=0,01) anos, em dentes com e sem lesões periapicais, respectivamente, houve decréscimos significantes na massa molar do material obturador. A infecção bacteriana participa no processo de degradação do polímero. O envelhecimento da guta-percha é um fator que influencia o sucesso a longo prazo do tratamento endodôntico. Após 15 anos, a longevidade do tratamento pode ser significantemente afetada pela redução da capacidade de selamento causada pela perda de massa molar do polímero, permitindo a reinfecção do sistema de canais radiculares.