Antibacterial activity of a plant extract and its potential for disinfecting gutta-percha cones.

This study evaluated the antibacterial activity of Rosmarinus officinalis extract and its potential for disinfecting guttapercha (GP) cones. In the first experiment, a hydro-alcoholic extract of Rosmarinus officinalis (leaves) in a dilution ratio of 10% m/v was tested against Enterococcus faecalis by using the disk diffusion method. Positive and negative controls were 70% cereal alcohol and antibiotics, respectively. The procedures were performed in triplicate, and the diameters of the zones of growth inhibition were measured with a caliper after 24 h at 37 degrees C. In the second experiment, the disinfection procedures were evaluated on GP cones artificially contaminated with Enterococcus faecalis. The R. officinalis extract was compared with 2% chlorhexidine digluconate and 2.5% sodium hypochlorite, using a direct exposure test (5 min treatment). Sterilized and non-disinfected cones were used as negative and positive controls, respectively. After 24 h of incubation, bacterial counts were taken. For both experiments, the data were statistically analyzed by Kruskall-Wallis and Tukey's tests (p < 0.05). The plant extract produced zones of inhibition comparable to those of tested antibiotics. Significant GP cone disinfection was verified with all disinfectant solutions, with no significant difference between them. R. officinalis extract showed bactericidal effect on Enterococcus faecalis and capacity to disinfect GP cones contamined with it.

Sealing ability of MTA-Angelus with propyleneglycol in furcal perforations.

This study evaluated the sealing ability of gray MTA-Angelus mixed with propyleneglycol in furcal perforations using a bacterial leakage test. Furcal perforations were created in 30 human mandibular molars using a size 3 round bur The samples were divided randomly into 2 experimental groups (n=10) according to the mixing agent. In G1, the MTA powder was mixed with propyleneglycol, while distilled water was used in G2. A 3:1 powder-liquid ratio was used for both groups. The MTA was placed in the perforation with an MTA carrier and condensed with hand pluggers. Non-repaired (n=5) and totally sealed (n=5) perforations served as positive and negative controls, respectively. Bacterial leakage was assessed daily for 30 days in a double-chamber apparatus with Enterococcus faecalis. Data were analyzed using Fisher exact test (p < 0.05) for three leakage periods: 1st to 10th day (P1); 11th to 20th day (P2); and 21st to 30th day (P3). The positive control presented leakage in all specimens within the first 24 hours, while no leakage was observed in the negative control during the experimental period. Leakage was observed in five (50%) of the 10 samples of the propyleneglycol group (G1) and seven (70%) of the distilled water group (G2) by the 20th day, without significant difference between the groups in periods P1 and P2 (p = 0.137). The leakage was significantly lower for G1 than G2 in period P3 (50% versus 100%, respectively, p = 0.016). In this single aerobic bacterial leakage method, the use of propyleneglycol as a vehicle for gray MTA-Angelus increased its sealing ability in furcal perforations at the end of the 30-day experimental period.

Sealing ability of MTA-Angelus with propyleneglycol in furcal perforations

This study evaluated the sealing ability of gray MTA-Angelus mixed with propyleneglycol in furcal perforations using a bacterial leakage test. Furcal perforations were created in 30 human mandibular molars using a size 3 round bur. The samples were divided randomly into 2 experimental groups (n=10) according to the mixing agent. In G1, the MTA powder was mixed with propyleneglycol, while distilled water was used in G2. A 3:1 powder-liquid ratio was used for both groups. The MTA was placed in the perforation with an MTA carrier and condensed with hand pluggers. Nonrepaired (n=5) and totally sealed (n=5) perforations served as positive and negative controls, respectively. Bacterial leakage was assessed daily for 30 days in a double-chamber apparatus with Enterococcus faecalis. Data were analyzed using Fisher exact test (p<0.05) for three leakage periods: 1st to 10th day (P1); 11th to 20th day (P2); and 21st to 30th day (P3). The positive control presented leakage in all specimens within the first 24 hours, while no leakage was observed in the negative control during the experimental period. Leakage was observed in five (50%) of the 10 samples of the propyleneglycol group (G1) and seven (70%) of the distilled water group (G2) by the 20th day, without significant difference between the groups in periods P1 and P2 (p=0.137). The leakage was significantly lower for G1 than G2 in period P3 (50% versus 100%, respectively, p=0.016). In this single aerobic bacterial leakage method, the use of propyleneglycol as a vehicle for gray MTAAngelus increased its sealing ability in furcal perforations at the end of the 30-day experimental period.

Este estudo avaliou a capacidade de selamento do MTA-Angelus cinza manipulado com propilenoglicol em perfuracoes de furca usando um teste de infiltracao bacteriana. Perfuracoes de furca foram criadas em 30 molares inferiores usando uma broca esferica numero 3. As amostras foram divididas aleatoriamente em dois grupos experimentais (n=10) de acordo com o agente de manipulacao. Em G1, o po do MTA foi manipulado com propilenoglicol enquanto que a agua destilado foi utilizada no G2. A proporcao po-liquido de 3:1 foi usada para ambos os grupos. O MTA foi colocado na perfuracao com uma porta- MTA e condensado com condensadores manuais. Perfuracoes nao-reparadas (n=5) e totalmente impermeabilizadas (n=5) serviram como controle positivo e negativo, respectivamente. A infiltracao bacteriana foi verificada diariamente durante 30 dias em um aparato de dupla camara com Enterococcus faecalis. Os dados foram analisados pelo teste exato de Fisher (p<0,05) para tres periodos: 1o ao 10o dia (P1), 11o ao 20o dia (P2) e do 21o ao 30o dia (P3). O controle positivo apresentou infiltracao em todas as amostras nas primeiras 24 horas, enquanto nenhuma infiltracao foi observada no controle positivo durante o periodo experimental. Infiltracao foi observada em 5 (50%) das 10 amostras do grupo do propilenoglicol (G1) e 7 (70%) do grupo da agua destilada no 20o dia, sem diferenca significativa entre o grupos nos periodos P1 e P2 (p=0,0137). A infiltracao foi significantemente menor para G1 que para G2 no periodo P3 (50% versus 100%, respectivamente, p=0,016). Neste metodo de infiltracao de apenas uma bacteria aerobica, o uso do propilenoglicol como veiculo para o MTA-Angelus cinza aumentou sua capacidade de selamento em perfuracoes de furca no final do periodo experimental de 30 dias.

Linear measurements to determine working length of curved canals with fine files: conventional versus digital radiography.

This in vitro study compared conventional and digital radiographic linear measurements to determine the working length (WL) of curved canals with fine endodontic files. In total, 30 mesiobuccal root canals in molars were measured with a #06 K-file to a length 1 mm short of the apical foramen (WL1). Teeth were mounted in plastic blocks and standardized periapical radiographs were obtained by conventional and digital (Digora Optime) radiographic methods with #06, #08 and #10 K-files positioned in WL1. Two independent and calibrated examiners performed the conventional measurements with a millimeter ruler, from the file stop to the file tip (WL2). For the digital images, examiners used the linear measurement tool on the Digora software, in original mode (WL3). For comparison of WL1, WL2 and WL3, the Wilcoxon test (P < 0.05) was applied and the reproducibility of the measurements was assessed. There was no statistically significant difference between Wl2 and Wl3 for #06, #08 and #10 K-files (P = 0.341, 0.641 and 0.232, respectively), with an acceptable level of interexaminer agreement. The measurements of Wl2 and Wl3 were significantly (P < 0.05) larger than those of WL1. No difference was observed among the linear measures obtained with either radiographic method, which showed higher WL values than the direct measurements.

Sealing ability of MTA used as cervical barrier in intracoronal bleaching.

The aim of this study was to compare the sealing ability of white mineral trioxide aggregate (MTA) with that of other materials used as a cervical barrier during intracoronal bleaching. Thirty eight extracted teeth were endodontically treated and 3 mm of filling was removed to receive the barrier material: G1-Coltosol; G2 - Vidrion R; G3 - White MTA; G4-No barrier (negative control) and G5- Roots totally protected with three layers of cyanoacrylate (positive control). The 30% hydrogen peroxide associated with the sodium perborate was left in the pulp chamber for 24 h. The specimens were immersed in a test tube containing a solution of potassium chromate (yellow), which turns blue in the presence ofhydrogen peroxide. Two calibrated evaluators scored according to color in the presence of the detecting solution (0 - unaltered color, 1 - light blue and 2 - dark blue). Data were analyzed by the Kruskall-Wallis test (p<0.05). The results showed no statistically significant differences between the experimental group G3 and positive control (G5). No statistically significant difference was observed between G1 and G3. However a statistical difference was verified between G2 and G3. MTA presented higher sealing ability than Vidrion R and did not differ from the positive control. However there was no difference between MTA and Coltosol.

Sealing ability of MTA used as cervical barrier in intracoronal bleaching

The aim of this study was to compare the sealing ability of white mineral trioxide aggregate (MTA) with that of other materials used as a cervical barrier during intracoronal bleaching. Thirty eight extracted teeth were endodontically treated and 3 mm of filling was removed to receive the barrier material: G1- Coltosol; G2 - Vidrion R; G3 - White MTA; G4-No barrier (negative control) and G5- Roots totally protected with three layers of cyanoacrylate (positive control). The 30% hydrogen peroxide associated with the sodium perborate was left in the pulp chamber for 24 h. The specimens were immersed in a test tube containing a solution of potassium chromate (yellow), which turns blue in the presence of hydrogen peroxide. Two calibrated evaluators scored according to color in the presence of the detecting solution (0 - unaltered color, 1 - light blue and 2 - dark blue). Data were analyzed by the Kruskall-Wallis test (p<0.05). The results showed no statistically significant differences between the experimental group G3 and positive control (G5). No statistically significant difference was observed between G1 and G3. However, a statistical difference was verified between G2 and G3. MTA presented higher sealing ability than Vidrion R and did not differ from the positive control. However, there was no difference between MTA and Coltosol.

O objetivo deste estudo foi comparar a capacidade de selamento do agregado trioxido mineral (MTA) branco com outros materiais usados como barreiras cervicais durante clareamento intra-coronario. Trinta e oito dentes extraidos foram endodonticamente tratados e 3 mm de obturacao foi removida para receber o material da barreira: G1- Coltosol; G2 - Vidrion R; G3 - MTA branco; G4-Nenhuma barreira (controle negativo) e G5- Raizes totalmente protegidas com tres camadas de cianocrilato (controle positivo). Peroxido de hidrogenio a 30% (PH) associado com perborato de sodio foi deixado na camara pulpar por 24 h. As amostras foram imersas em tubos de ensaio contendo uma solucao de cromato de potassio (amarela) que se torna azul na presenca de peroxido de hidrogenio. Dois avaliadores calibrados atribuiram escores de acordo com a cor obtida na solucao detectora (0 - cor inalterada, 1 - azul claro e 2 - azul escuro). Os dados foram analisados pelo teste de Kruskall-Wallis (p<0,05). Os resultados nao mostraram diferencas estatisticamente significantes entre o grupo experimental G3 e o controle positivo (G5). Nenhuma diferenca estatisticamente significante foi observada entre G1 e G3. Entretanto, diferenca estatistica foi verificada entre G2 e G3. MTA apresentou maior habilidade de selamento que o Vidrion R e nao diferiu do controle positivo. Entretanto, nao houve diferenca entre MTA e Cotosol.