Effect of time of extraction on the biocompatibility of endodontic sealers with primary human fibroblasts

The aim of this work was to evaluate the effects of different times of extraction on the cytotoxicity of six representatives of different root canal sealer groups-Real Seal SE, AH Plus, GuttaFlow, Sealapex, Roth 801, and ThermaSeal Plus-with human gingival fibroblasts. The materials were prepared according to manufacturers' specifications, and were incubated in culture medium (DMEM) at 37ºC for 1, 7, 14, 21, and 28 days, with daily washing, to simulate periodontal ligament clearance. Human fibroblasts were exposed to the final extracts at 24 hours, and cell viability was determined by MTT assay, with exposure to unconditioned DMEM as a negative control. Statistical analysis comparing cytotoxicities at each exposure time was performed by ANOVA with Scheffé adjustment for multiple comparisons at a 95% confidence level. Results indicated that GuttaFlow was significantly less cytotoxic than all other sealers (p < 0.05) at 1 day of extraction. After 7 days of extraction, cell viability for GuttaFlow was significantly increased as compared with that of all groups except sealer AH Plus. At day 14, cytotoxicity of Sealapex was significantly higher than that of all other sealers (p < 0.05). At days 21 and 28, there were no significant differences in cytotoxicity among sealer groups. All materials presented some level of cytotoxicity to fibroblasts, while GuttaFlow was the least cytotoxic sealer tested. However, the cytotoxicity of all materials seemed to decrease similarly in a time-dependent manner.

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.

Avaliaçäo da cicotoxicidade de três marcas de cones de guta-percha. Estudo experimental em tecido subcutâneo de ratos / Study of the citotoxicity of three differents commercial brands (brasilian made) of gutta-percha

O autor estudou o comportamento do tecido conjuntivo de rato frente a três marcas de cones de guta-percha de fabricaçäo nacional. No prazo inicial de 7 dias, todos os produtos testados apresentaram reaçäo inflamatória intensa. Os cones de guta-percha fabricados pelas firmas Dentsply, Tanari e a substância controle (soro fisiológico) foram bem toleradas após o implante de 30 a 60 dias, o mesmo näo acontecendo com os da marca Odame