Comparative study of the cytotoxic effect of Resilon against two cell lines.

Resilon is a new material that is a candidate to replace gutta-percha as a root filling material. This study evaluated the antiproliferative effect of Resilon and two commercially available gutta-percha points (Roeko, Dentsply). Two established cell lines (L929 and RPC-C2A) were used for the experiment. Cell survival fraction was estimated by the sulforhodamine-B assay, in reference to controls after 48-h exposure. Non-parametric tests (Kruskal-Wallis followed by Dunn's multiple comparisons) were used to evaluate the statistical significance of the results (alpha=0.05). Cytotoxicity in a descending order was: Resilon > Roeko gutta-percha > Dentsply gutta-percha. At 24-h exposure, no statistically significant differences (p>0.05) were observed between tested materials in both cell lines. At 48-h exposure, statistically significant differences (p<0.05) were found between Resilon and the other materials in the L929 cell line. In the RPC-C2A cell line Resilon was significantly more cytotoxic than Dentsply gutta-percha (p<0.05), but no statistically significant differences (p>0.05) were found between Resilon and Roeko gutta-percha. The cytotoxicity of Resilon increased significantly from 24 h to 48 h in both cell lines. Resilon points were more cytotoxic than gutta-percha points. The cytotoxicity was time dependent and increased after 48 h.

Comparative study of the cytotoxic effect of resilon against two cell lines

Resilon is a new material that is a candidate to replace gutta-percha as a root filling material. This study evaluated the antiproliferative effect of Resilon and two commercially available gutta-percha points (Roeko, Dentsply). Two established cell lines (L929 and RPC-C2A) were used for the experiment. Cell survival fraction was estimated by the sulforhodamine-B assay, in reference to controls after 48-h exposure. Non-parametric tests (Kruskal-Wallis followed by Dunn's multiple comparisons) were used to evaluate the statistical significance of the results (α=0.05). Cytotoxicity in a descending order was: Resilon > Roeko gutta-percha > Dentsply gutta-percha. At 24-h exposure, no statistically significant differences (p>0.05) were observed between tested materials in both cell lines. At 48-h exposure, statistically significant differences (p<0.05) were found between Resilon and the other materials in the L929 cell line. In the RPC-C2A cell line Resilon was significantly more cytotoxic than Dentsply gutta-percha (p<0.05), but no statistically significant differences (p>0.05) were found between Resilon and Roeko gutta-percha. The cytotoxicity of Resilon increased significantly from 24 h to 48 h in both cell lines. Resilon points were more cytotoxic than gutta-percha points. The cytotoxicity was time dependent and increased after 48 h.

Resilon é um material novo com potencial para substituir a guta-percha como material obturador radicular. Este estudo avaliou o efeito anti-proliferativo do Resilon e de duas marcas comerciais de pontas de guta-percha (Roeko e Dentsply). Para os fins deste estudo foram utilizadas duas linhagens celulares conhecidas (L929 e RPC-C2A). A fração de sobrevivência celular foi estimada pelo método colorimétrico de sulforodamina B comparado aos controles após exposição por 48 h. A significância estatística dos resultados (α=0,05) foi avaliada pelos testes não-paramétricos de Kruskal-Wallis e Dunn para comparações múltiplas. A citotoxicidade dos materiais em ordem decrescente foi: Resilon > guta-percha Roeko > guta-percha Dentsply. Após 24 h de exposição, não foram encontradas diferenças estatisticamente significantes (p>0,05) entre os materiais testados em ambas as linhagens celulares. Após 48 h, o Resilon apresentou um efeito citotóxico significantemente maior (p<0,05) em comparação aos outros dois materiais na linhagem celular L929. Na linhagem RPC-C2A, a citotoxicidade do Resilon foi significantemente maior (p<0,05) que a da guta-percha Dentsply, mas não houve diferenças significantes (p<0,05) entre Resilon e guta-percha Roeko. A citotoxicidade do Resilon aumentou significativamente de 24 para 48 h para ambas as linhagens celulares. As pontas de Resilon foram mais citotóxicas do que as pontas de guta-percha. A citotoxicidade foi tempo-dependente e aumentou após 48 h de exposição.

Comparative study of the sealing ability of a polydimethylsiloxane-based root canal sealer

O objetivo deste estudo foi comparar a capacidade de selamento de três cimentos endodônticos, RSA (cimento à base de silicone), Endion (cimento à base de ionômero de vidro) e Topseal (cimento à base de resina epóxica), com e sem remoção de smear layer. Noventa dentes humanos extraídos foram selecionados e distribuídos em 6 grupos (n=15), de acordo com os seguintes protocolos: em 3 grupos, a smear layer foi mantida e os canais radiculares foram obturados com cones de guta-percha e com os cimentos RSA, Endion e Topseal, respectivamente. Nos outros 3 grupos, a smear layer foi removida e os canais radiculares foram obturados da mesma forma. A microinfiltração foi avaliada aos 7 dias, 1 mês e 2 meses, utilizando o sistema de transporte de fluído. Os resultados foram expressos em µL/24 h. Os dados foram analisados estatisticamente por meio dos testes não-paramétricos de Kruskall-Wallis e Mann-Whitney. Os resultados demonstraram que o grupo obturado com Topseal sem smear layer apresentou infiltração significativamente menor (p<0.05) que o grupo obturado com cimento RSA sem smear layer, em todos os períodos avaliados. Não houve diferença estatisticamente significante (p>0.05) entre os outros grupos, nos intervalos de avaliação estabelecidos. Os achados deste estudo demonstraram que o cimento à base de silicone (RSA) não apresentou melhor capacidade de selamento que os outros cimentos, na presença ou ausência de smear layer. Dentre os cimentos endodônticos avaliados, o Topseal apresentou os menores valores de microinfiltração.

Comparative study of the sealing ability of a polydimethylsiloxane-based root canal sealer.

The purpose of this study was to compare the sealing ability of three root canal sealers, RSA (polydimethylsiloxane sealer), Endion (glass-ionomer sealer) and Topseal (epoxy resin sealer), with and without smear layer removal. Ninety extracted human teeth were selected and assigned to 6 groups (n=15), according to the following protocols: in 3 groups, the smear layer was left intact and the root canals were obturated with gutta-percha points and RSA, Endion and Topseal, respectively; in the other 3 groups, the smear layer was removed and the root canals were obturated in the same way as described above. Microleakage was measured at 7 days, 1 month and 2 months, using the fluid transport model. The results were expressed in microL/24 h. Data were analyzed statistically by Kruskall-Wallis and Mann-Whitney non-parametric tests. The results showed that the Topseal group without smear layer leaked significantly less (p<0.05) than the RSA group without smear layer, at all experimental periods. No statistically significant differences (p>0.05) were found among the other groups, at the established evaluation intervals. The findings of this study showed that the polydimethylsiloxane sealer (RSA) did not yield better sealing ability than the other sealers, either in the presence or in the absence of smear layer. Topseal had the least microleakage from the root canal sealers evaluated.

Adhesion of a new methacrylate resin-based sealer to human dentin.

The purpose of this study was to compare the shear bond strength of four root canal sealers: Fibrefill (a methacrylate resin sealer), Endion (a glass ionomer sealer), Topseal (an epoxy resin sealer), and CRCS (a calcium hydroxide sealer) to human root canal dentin. The dentin specimens were divided into four groups of 12 specimens each and etched with 3 ml of EDTA 17% before rinsing with NaOCl 2.5% and distilled water. Bond strength was tested using a test machine by subjecting samples to a shear load at a cross-head speed of 0.5 mm/min. The best results were observed in the Fibrefill group, in which the mean shear bond strength was 7.993 +/- 2.365 MPa. The values in the Endion (1.816 +/- 0.614 MPa) and CRCS (2.224 +/- 0.509 MPa) groups were significantly lower than in the Fibrefill and Topseal (6.235 +/- 1.428 MPa) groups. Inspection of the fractured surfaces revealed the bond failure to be mainly adhesive to dentin for Fibrefill and cohesive for Endion sealer. CRCS and Topseal sealers showed both adhesive and cohesive failures.