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.

Experimentally induced anachoresis in the periapical region after root canal filling / Anacoresis inducida experimentalmente en la región periapical después de obturación del conducto radicular

Anachoresis is the phenomenon through which blood-borne bacteria, dyes, pigments and other materials are attracted and fixed to circumscribed areas of inflammation. This study evaluated the occurrence of anachoresis in the periapical region of dogs submitted to root canal fillings. One hundred and four roots from four dogs were endodontically treated and root canals were filled with zinc-oxide-eugenol cement. Fifty percent were filled up to the dentinocemental junction and the others were overfilled. At 120 days after root canal treatment, experimental bacteremia was induced by intravenous inoculation of 105 CFU Streptococcus pyogenes. The dogs were sacrificed 48 hours and 30 days after the bacteremia. Culture and DNA amplification by PCR revealed the presence of the inoculated bacteria just in periapical tissues of dogs sacrificed 48 hours after bacteremia and not in animals sacrificed after 30 days. AP-PCR fingerprints of recovered colonies of S. pyogenes and the presence of genetic markers of resistance to antimicrobials were similar to the inoculated strain. Endodontically treated periapices seemed to be prone to the occurrence of anachoresis and there was no relationship between the phenomenon and the level of root canal filling.

Anacoresis es el fenómeno por el cual las bacterias transmitidas por la sangre, colorantes, pigmentos y otros materiales se atraen y se fija a zonas circunscritas de la inflamación. Este estudio evaluó la incidencia de anacoresis en la región periapical de los perros presentados a raíz de los rellenos del canal. Un total de ciento cuatro raíces de cuatro perros fueron tratados con endodoncia y tratamientos de conducto se rellena con cemento de óxido de zinc-eugenol. El cincuenta por ciento estaban llenos hasta el cruce dentinocemental y los otros se llene en exceso. A los 120 días después del tratamiento de conducto radicular, bacteriemia experimental fue inducida por la inoculación intravenosa de 105 UFC por Streptococcus pyogenes. Los perros fueron sacrificados 48 horas y 30 días después de la bacteriemia. La cultura y la amplificación del ADN por PCR reveló la presencia de las bacterias inoculadas sólo en los tejidos periapicales de los perros sacrificados 48 horas después de la bacteriemia y no en los animales sacrificados después de 30 días. AP-PCR huellas dactilares de las colonias recuperadas de S. pyogenes y la presencia de marcadores genéticos de resistencia a los antimicrobianos fueron similares a la cepa inoculada. Periápices endodonciados parecía ser propensos a la ocurrencia de anacoresis y no había ninguna relación entre el fenómeno y el nivel de llenado del conducto radicular.

Synergistic growth effect among bacteria recovered from root canal infections

The objective of this study was to determine the ecological relationships between bacterial species that colonize infected root canals. Root canal bacteria recovered from one patient with pulp canal necrosis were evaluated in vitro for synergistic and antagonistic activities determined by mono and co-culture growth kinetics and the production of bacteriocin-like substances using the double layer diffusion method. Peptostreptococcus prevotii triggered a significant increase of Fusobacterium nucleatum growth, while the former bacteria did not affect the growth of P. prevotii. The bacterial species did not produce antagonism activity against itself or against any of the other two species. Despite many studies have demonstrated the capability of root canal microorganisms to produce antagonistic substances, these in vitro experimental tests show the synergistic effect of P. prevotii on the growth of F. nucleatum.

Prevalence of periodontal bacteria in saliva of Kuwaiti children at different age groups

Aggregatibacter [formerly Actinobacillus] actinomycetemcomitans, Tannerella forsythensis and Porphyromonas gingivalis and to a lesser extent Prevotella intermedia and Prevotella nigrescens, are Gram-negative species that are associated with destructive periodontitis. Studies from different parts of the world have shown variable detection rates of periodontal organisms. Hardly any data exist on their carriage in children living in the Middle East. This study was designed to determine the detection of these species in the oral cavity of 240 generally healthy Kuwaiti children, divided into five age groups:<6 years [n=40], 6-9 years [n=60], 10-12 years [n=40], 13-15 years [n=40] and 16-18 years [n=60]. Saliva was used as the microbiological specimen, and the samples were analyzed by molecular methods using multiplex PCR. A total of 185 [77.1%] of the 240 children were colonized by at least one of the target periodontal bacteria. In all age groups, P. nigrescens was the most prominent and detected in saliva of 15%, 32%, 63%, 50%, and 47% of the children at the five age groups, respectively. P. gingivalis was detected only occasionally. Only few pathogens were found before the permanent dentition, i.e. at the age of<6 years. The highest carriage rates were from the groups between 6 and 15 years of age. The salivary carriage of the pathogens was essentially similar in the age groups of 10-12 years and 13-15 years. In conclusion, except for P. gingivalis, the examined periodontal pathogens are relatively common findings in Kuwaiti children and colonize the oral cavity from childhood onwards

Distribuiçäo de bactérias planctônicas, colônias bacterianas e biofilmes microbianos em dentes decíduos com pulpite e ou necrose pulpar / Distribution of bacterial plankton, bacterial colonies and microbial biofilm on deciduous teeth with pulpitis and pulp necrosis

As bactérias constituem fatores primordiais da contaminaçäo da polpa dentária de dentes decíduos resultando em implicaçöes clínicas e terapêuticas. Com a finalidade de analisar a presença de bactérias planctônicas, colônias e biofilmes microbianos nas estruturas de dentes decíduos portadores de pulpite e necrose pulpar, utilizaram-se 32 dentes decíduos com cárie profunda. Dezesseis dentes foram seccionados no sentido longitudinal e o restante no sentido transversal. Os espécimes foram corados pela hematoxilina-eosina de Harris e Brown e Brenn para análise pela microscopia óptica. A partir da metodologia empregada pôde-se verificar que: 1) Em dentes decíduos com pulpite decorrente de cárie dentária, as bactérias podem ser encontradas nos túbulos dentinários e especialmente no interior do tecido pulpar na área inflamada. Colônias bacterianas e biofilmes microbianos säo visualisados na superfície cariosa e nos focos de liquefaçäo dentinária; 2) As bactérias plactônicas, colônias bacterianas e biofilmes microbianos estäo abundantemente presentes nas câmaras pulpares e canais radiculares de dentes decíduos com necrose pulpar, localizando-se nas superfícies do teto, do soalho da câmara pulpar, nas paredes laterais do canal radicular e, por extensäo, nas paredes externas apicais...

Detecçäo de anticorpos IgG para o Bacteroides (Porphyromanas) gingivalis e Bacteroides Intermedius (Prevotella intermedia) em lesöes periapicais crônicas pela técnica de imunofluorescência indireta / The verify the presence of immunoglobulin G with anticorpic specificity to the Bacteroides intermedius and Bacteroides gingivalis by employing the immunofluorescence technique

Lesöes periapicais crônicas foram avaliadas pela técnica de imunofluorescência indireta com o propósito de estimar a presença de anticorpos IgG específicos para o Bacteroides gingivalise Bacteroides intermedius. Das 15 amostras examinadas, 7 (46,6 por cento) apresentaram reatividade anticórpica

Aspectos inmunológicos de las patologías periapicales / Immunological aspects of the periapical pathology

Estudia el papel de los fenómenos en el establecimiento y mantenimiento o reparación de las patologías periapicales basandose en la revisión bibliográfica existente, se evalúa lo ya reportado y se aportan conclusiones sobre aspectos nuevos de esa información