In vitro antibacterial activity of a silicone-based endodontic sealer and two conventional sealers

Abstract The aim of this study was to evaluate whether the modification in the silver component is capable of providing GuttaFlow 2 with antibacterial activity against Enterococcus faecalis compared with epoxy resin-based (AH Plus) and zinc oxide and eugenol-based (Endofill) sealers. The antibacterial activity was evaluated using a reference strain of E. faecalis (ATCC 29212). Freshly mixed sealers were subjected to the agar diffusion test (ADT), while the direct contact test (DCT) was performed after materials setting. ADT results were obtained through measurements, in millimeters, of the inhibition zones promoted by the materials, using a digital caliper. In DCT, values of CFU/mL promoted by the three sealers were compared in three experimental periods (1 min, 1 h, and 24 h). The data were analyzed using Kruskal-Wallis and Dunn post-hoc tests (p < 0.05). In both ADT and DCT, GuttaFlow 2 presented no effect against E. faecalis, while Endofill and AH Plus showed similar inhibition zones. Endofill was the only material capable of reducing bacterial growth in DCT. In conclusion, modifications in the silver particle of GuttaFlow 2 did not result in a sealer with antibacterial effect against E. faecalis.

Avaliação do hipoclorito de sódio e da clorexidina na desinfecção de cones de Guta-Percha / Evaluation of sodium hypochlorite and chlorhexidine in disinfection Gutta-Percha cones

Introdução: O objetivo deste trabalho é avaliar a eficácia, em dois períodos de tempo, do hipoclorito de sódio e da clorexidina na desinfecção de cones de guta-percha. Métodos: Foram utilizados 50 cones de gutapercha previamente contaminados com cepas de bactérias do gênero Enterococcus faecalis (ATCC 29212), em culturas puras. Para o processo de descontaminação, os cones foram divididos em quatro grupos, contendo 10 amostras cada: G1- hipoclorito de sódio (NaOCl) a 5,25% por 30 segundos; G2 - NaOCl a 5,25% por 1 minuto; G3 - clorexidina a 4% por 30 segundos; G4 - clorexidina a 4% por 1 minuto. Após esse período, os cones foram introduzidos individualmente em tubos de ensaio contendo caldo de BHI, mantidos em estufa bacteriológica a 37ºC por 72 horas, quando foi avaliada a presença de contaminação através da turvação do meio. Para o grupo-controle positivo, empregaram-se 2 cones, que foram contaminados e colocados em tubos de ensaio e, para o controle negativo, 8 cones foram apenas descontaminados, sendo colocados 2 cones em cada uma das soluções desinfetantes, por 30 segundos e por 1 minuto. Resultados: Verificou-se a ausência de crescimento bacteriano nos grupos 1, 2, 3 e 4, em todos os períodos experimentais. No controle positivo, houve 100% de contaminação e, no controle negativo, ausência de crescimento bacteriano. Conclusão: As soluções de NaOCl a 5,25% e de clorexidina a 4%, por períodos de tempo de 30 segundos e de 1 minuto, possuem efetividade antimicrobiana contra o Enterococcus faecalis, podendo ser utilizadas na desinfecção de cones de guta-percha nos tempos testados.

Introduction: The aim of this study is to evaluate the efficacy, in two period of time, of sodium hypochlorite and chlorhexidine in disinfection gutta-percha cones. Methods: 50 gutta-percha cones were used, previously contaminated with bacteria of the genus Enterococcus faecalis (ATCC 29212), in pure cultures. For the decontamination process, the cones were divided into four groups, containing 10 samples each: G1- sodium hypochlorite 5,25% for 30 seconds; G2 - sodium hypochlorite 5,25% for 1 minute; G3 - chlorhexidine 4% for 30 seconds; G4 - chlorhexidine 4% for 1 minute. After this period, all cones were immersed individually in test tubes containing Brain Heart Infusion, maintained in bacteriological incubator at 37ºC for 72 hours, when was evaluated the presence of contamination through the turbidity of BHI solution. For the positive control groups, were used 2 gutta-percha cones that were contaminated and placed directly in test tubes and for the negative control group 8 cones were just decontaminated, being placed 2 cones in each disinfectant solution, for 30 seconds and for 1 minute. Results: There was the absence of bacterial growth in groups 1, 2, 3 and 4, in all experimental periods. In the positive control group were verified 100% of contamination and in the negative control tubes wasn't verified the presence of bacterial growth. Conclusion: The solutions of 5,25% sodium hypochlorite and 4% chlorhexidine for 30 seconds and 1 minute have antimicrobial effectiveness against Enterococcus faecalis, which can be used in the disinfection of gutta-percha cones in the time tested.

Evaluation of subcutaneous and alveolar implantation surgical sites in the study of the biological properties of root-end filling endodontic materials

OBJECTIVE: The aim of this study was to compare two methodologies used in the evaluation of tissue response to root-end filling materials in rats. MATERIAL AND METHODS: Forty rats were divided into 4 groups: in Groups I and II (control groups), empty polyethylene tubes were implanted in the extraction site and in the subcutaneous tissue, respectively; in Groups III and IV, polyethylene tubes filled with ProRoot MTA were implanted in the extraction site and in the subcutaneous tissue, respectively. The animals were killed 7 and 30 days after tube implantation, and the hemi-maxillas and the capsular subcutaneous tissue, both with the tubes, were removed. Specimens were processed and evaluated histomorphologicaly under light microscopy. The scores obtained were analyzed statistically by the Kruskal-Wallis test (p<0.05). RESULTS: There were no statistically significant differences between the implantation methods (p=0.78033, p=0.72039). It was observed that the 30-day groups presented a more mature healing process due to smaller number of inflammatory cells. CONCLUSIONS: The present study showed no differences in tissue responses as far as the implantation site and the studied period were concerned. Alveolar socket implantation methodology represents an interesting method in the study of the biological properties of root-end filling endodontic materials due to the opportunity to evaluate bone tissue response.

Efetividade de solventes e de técnicas na desobturaçäo dos canais radiculares: estudo in vitro / Effectiveness of solvents and techniques for removal of filling material from root canals: a study in vitro

Neste estudo avaliou-se a efetividade de cinco solventes de guta-percha agindo por cinco e 10 minutos, e de quatro técnicas de desobturaçäo de canais radiculares. Nas duas partes do experimento procurou-se empregar metodologias que mais se aproximassem das aplicaçöes clínicas, bem como os materiais e técnicas mais usuais. Testou-se também, um procedimento complementar de desobturaçäo, no intuito de abreviar e melhorar a remoçäo dos remanescentes de materiais nos retratamentos, antes do início da reinstrumentaçäo. Verificou-se que, entre os solventes testados, o clorofórmio foi o mais eficiente e a técnica de desobturaçäo com o uso da broca de Gates-Glidden e limas endodônticas foi a mais rápida e eficaz. O procedimento complementar, com algodäo envolto na lima e embebido em solvente, melhorou os resultados de todas as técnicas testadas

Cones de prata: avaliaçäo in vitro do poder bacteriostático

Cones de prata de diversos calibres, empregados na obturaçäo de canais radiculares, tiveram sua açäo antimicrobiana testada, através da verificaçäo do halo de inibiçäo de crescimento de cepas de três diferentes bactérias (Staphylococcus aureus, Streptococcus viridans e Pseudomonas aeruginosa) em ágar nutritivo. Confirmou-se o poder bacteriostático. Consideraçöes sobre a utilizaçäo dos cones de prata como material obturador de canais radiculares foram feitas respaldadas em conflitante revisäo bibliográfica