Orientador: Brenda Paula Figueiredo de Almeida Gomes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-08T05:23:39Z (GMT). No. of bitstreams: 1 Jacinto_RogeriodeCastilho_D.pdf: 1193443 bytes, checksum: cc178c0781498658e7784945f13b0757 (MD5) Previous issue date: 2007 / Resumo: Os objetivos deste estudo foram analisar a microbiota de canais radiculares com necrose e com lesão periapical de dentes sintomáticos e assintomáticos; quantificar a presença de endotoxinas; correlacionar a presença de bactérias específicas e a quantidade de endotoxinas com os sinais e sintomas de origem endodôntica; e investigar a suscetibilidade antimicrobiana de bactérias anaeróbias estritas isoladas dos canais radiculares contra 8 antibióticos, usando o E-test. Amostras microbiológicas foram coletadas de 90 canais radiculares com polpa necrosada e processadas por meio de técnicas microbiológicas. Outras 50 amostras foram obtidas de canais radiculares necrosados, sintomáticos e assintomáticos para realização do teste cromogênico para quantificação das endotoxinas. Análise estatística foi feita pelos testes x2 de Person ou de Fisher. Um total de 400 isolados clínicos foi encontrado, os quais pertenciam a 69 diferentes espécies e 22 diferentes gêneros. Oitenta por cento das bactérias eram anaeróbias estritas e F. nucleatum foi a espécie predominante. Canais radiculares de dentes sintomáticos apresentaram uma predominância de anaeróbios estritos e um número maior de espécies por canal radicular em relação aos dentes assintomáticos. Foi observada uma relação entre grupos microbianos específicos, principalmente anaeróbios Gram-negativos e a presença de dor espontânea ou dor prévia, dor à percussão, dor à palpação e edema. Endotoxinas foram encontradas em altas concentrações em canais radiculares de dentes sintomáticos e houve uma correlação positiva entre os sinais e sintomas e a concentração de endotoxinas. Amoxicilina, amoxicilina associada ao ácido clavulânico e cefaclor foram efetivos contra todas as cepas testadas. Os resultados sugerem que bactérias específicas e endotoxinas estão associadas aos sinais e sintomas de dentes com canais infectados e lesão periapical e que, a maioria das espécies anaeróbias testadas foi suscetível aos antibióticos estudados / Abstract: The aim of this study was to analyse the microflora isolated from infected root canals of symptomatic or asymptomatic teeth, to quantify the presence of endotoxins; to correlate the presence of specific bacteria and the amount of endotoxins with endodontic symptomatology; and to investigate the antibiotic susceptibility of anaerobic bacteria isolated from infected teeth with periapical lesions against 8 antibiotics through the E-test. Microbial samples were taken from 90 root canals of teeth with necrotic dental pulp, and analysed using rigorous culture procedures. Other 50 samples were collected from infected symptomatic or asymptomatic root canals in order to be analysed by a chromogenic test for the endotoxin quantification. Statistical analysis used a Pearson x2 test or a one-sided Fisher's Exact test, as appropriate. A total of 400 cultivable isolates were recovered from 69 different microbial species and 22 different genera. Eight per cent of the bacteria were were strict anaerobes and F. nucleatum was the most frequently isolated species. Root canals from symptomatic teeth harboured more obligate anaerobes and a larger number of bacterial species than the asymptomatic teeth. Relationships were found between specific microorganisms, especially Gram-negative anaerobes and the presence of pain or history of pain, tenderness to percussion, pain to palpation and swelling. High concentrations of endotoxins were found in root canals of symptomatic teeth and there was a positive correlation between endodontic signs and symptoms and the concentration of endotoxins in infected root canals. Amoxicillin, amoxicillin + clavulanate and cephaclor were effective against all the strains tested. Our results suggested that specific bacteria and endotoxins are associated with endodontic symptoms of infected teeth and that the majority of the anaerobic species tested was susceptible to all antibiotics studied. / Doutorado / Endodontia / Doutor em Clínica Odontológica

Indiana University-Purdue University Indianapolis (IUPUI) / The primary goal of root canal treatment is to eliminate microbes from the root canal system, which is the cause of pulpal and periapical infections. Research shows that after a single visit of chemomechanical debridement microbes continue to remain within the canal system. An interappointment medication step has been advocated to maximize potential elimination of microbes within the root canal system. Previous studies have shown propolis to be antibacterial against common endodontic microbes. Studies have shown trends in different microbes being present in primary verus secondary endodontic infections. The majority of literature has focused on the efficacy of propolis against Enterococcus faecalis, a microbe commonly implicated in secondary endodontic 95 infections. The aim of this study was to demonstrate the efficacy of propolis against Fusobacterium nucleatum, a microbe commonly found in primary endodontic infections. This study aims to demonstrate the efficacy of propolis against a bacterium of primary endodontic infections (F. nucleatum) as well as against microbial biofilm to further support its potential use as a novel intracanal medicament. Dilutions of propolis were added to cultures of F. nucleatum in microtiter plates in a range from 390 μg/ml to 50,000 μg/ml. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and the minimum biofilm inhibitory concentration (MBIC) were determined. The MIC was determined of the total solution (biofilm+planktonic), planktonic, and biofilm (MBIC) after a 48-hour incubation period. The MBIC was determined by fixing biofilm to the wells and using crystal violet staining with spectrophotometry. The MBC was examined by plating solution from each concentration test well and reading the plates after 48 hours of incubation. The results show that the MIC of the total (biofilm+planktonic) appears to occur at a concentration of 6250 μg/ml. The MBIC appears to occur at the concentration of 1562.5 μg/ml. The planktonic results exhibit no significant difference in test and control wells. There was no MBC at any of the test concentrations. The propolis appears to inhibit bacterial growth and biofilm formation but does not appear to be bactericidal at any of the tested concentrations. The results of this study indicate that propolis has an MIC and MBIC when tested in vitro against F. nucleatum, although it does not show an MBC. There appears to be potentially significant interaction of propolis with biofilm as displayed by the lower concentration needed to exibit inhibitory effects on biofilm formation. This information 96 may contribute to the ability to develop a proper concentration of propolis to use in vivo when treating endodontic infections.