Journal of endodontics · 2011
Setting properties and cytotoxicity evaluation of a premixed bioceramic root canal sealer.
Сравнительное исследованиеСтатьяНазвание и аннотация: Перевод в очереди
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Loushine Bethany A, Bryan Thomas E, Looney Stephen W, Gillen Brian M, Loushine Robert J, Weller R Norman, Pashley David H, Tay Franklin R
Аннотация
INTRODUCTION: This study investigated the setting time and micohardness of a premixed calcium phosphate silicate-based sealer (EndoSequence BC Sealer; Brasseler USA, Savannah, GA) in the presence of different moisture contents (0-9 wt%). The moisture content that produced the most optimal setting properties was used to prepare set EndoSequence BC Sealer for cytotoxicity comparison with an epoxy resin-based sealer (AH Plus; Dentsply Caulk, Milford, DE).
METHODS: Standardized disks were created with BC Sealer, AH Plus, Pulp Canal Sealer EWT (positive control) (SybronEndo, Orange CA), and Teflon (Small Parts Inc., Miami Lakes, FL; negative control). Disks were placed in Transwell Inserts, providing indirect contact with MC3T3-E1 cells. Succinate dehydrogenase activity of the cells was evaluated over a 6-week period using MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cytotoxicity profiles of BC Sealer and AH Plus were fitted with polynomial regression models. The time for 50% of the cells to survive (T(0.5)) was analyzed using the Wald statistic with a two-tailed significance level of 0.05.
RESULTS: BC Sealer required at least 168 hours to reach the final setting using the Gilmore needle method, and its microhardeness significantly declined when water was included in the sealer (P = .004). All set sealers exhibited severe cytotoxicity at 24 hours. The cytotoxicity of AH Plus gradually decreased and became noncytotoxic, whereas BC Sealer remained moderately cytotoxic over the 6-week period. A significant difference (P < .001) was detected between T(0.5) of BC Sealer (5.10 weeks; 95% confidence interval [CI], 4.69-5.42, standard error [SE] = 0.09) and T(0.5) of AH Plus (0.86 weeks; 95% CI, 0.68-1.05; SE = 0.18).
CONCLUSIONS: Further studies are required to evaluate the correlation between the length of setting time of BC Sealer and its degree of cytotoxicity.
METHODS: Standardized disks were created with BC Sealer, AH Plus, Pulp Canal Sealer EWT (positive control) (SybronEndo, Orange CA), and Teflon (Small Parts Inc., Miami Lakes, FL; negative control). Disks were placed in Transwell Inserts, providing indirect contact with MC3T3-E1 cells. Succinate dehydrogenase activity of the cells was evaluated over a 6-week period using MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Cytotoxicity profiles of BC Sealer and AH Plus were fitted with polynomial regression models. The time for 50% of the cells to survive (T(0.5)) was analyzed using the Wald statistic with a two-tailed significance level of 0.05.
RESULTS: BC Sealer required at least 168 hours to reach the final setting using the Gilmore needle method, and its microhardeness significantly declined when water was included in the sealer (P = .004). All set sealers exhibited severe cytotoxicity at 24 hours. The cytotoxicity of AH Plus gradually decreased and became noncytotoxic, whereas BC Sealer remained moderately cytotoxic over the 6-week period. A significant difference (P < .001) was detected between T(0.5) of BC Sealer (5.10 weeks; 95% confidence interval [CI], 4.69-5.42, standard error [SE] = 0.09) and T(0.5) of AH Plus (0.86 weeks; 95% CI, 0.68-1.05; SE = 0.18).
CONCLUSIONS: Further studies are required to evaluate the correlation between the length of setting time of BC Sealer and its degree of cytotoxicity.