Fabio Aranha, Andreza MariaAparecida Giro, Elisa Maria [UNESP]Hebling, Josimeri [UNESP]Rosetti Lessa, Fernanda Camposde Souza Costa, Carlos Alberto [UNESP]2013-09-302014-05-202013-09-302014-05-202010-09-01Journal of Applied Oral Science. Bauru-sp: Univ São Paulo Fac Odontologia Bauru, v. 18, n. 5, p. 461-466, 2010.1678-7757http://hdl.handle.net/11449/15718This in vitro study evaluated the cytotoxicity of an experimental restorative composite resin subjected to different light-curing regimens. Methods: Forty round-shaped specimens were prepared and randomly assigned to four experimental groups (n=10), as follows: in Group 1, no light-curing; in Groups 2, 3 and 4, the composite resin specimens were light-cured for 20, 40 or 60 s, respectively. In Group 5, filter paper discs soaked in 5 mu L PBS were used as negative controls. The resin specimens and paper discs were placed in wells of 24-well plates in which the odontoblast-like cells MDPC-23 (30,000 cells/cm(2)) were plated and incubated in a humidified incubator with 5% CO(2) and 95% air at 37 degrees C for 72 h. The cytotoxicity was evaluated by the cell metabolism (MTT assay) and cell morphology (SEM). The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Results: In G1, cell metabolism decreased by 86.2%, indicating a severe cytotoxicity of the non-light-cured composite resin. on the other hand, cell metabolism decreased by only 13.3% and 13.5% in G2 and G3, respectively. No cytotoxic effects were observed in G4 and G5. In G1, only a few round-shaped cells with short processes on their cytoplasmic membrane were observed. In the other experimental groups as well as in control group, a number of spindle-shaped cells with long cytoplasmic processes were found. Conclusion: Regardless of the photoactivation time used in the present investigation, the experimental composite resin presented mild to no toxic effects to the odontoblast-like MDPC-23 cells. However, intense cytotoxic effects occurred when no light-curing was performed.461-466engDental materialsCytotoxicityDental pulpCultured cellsResumoS1678-77572010000500006WOS:000284590700006Acesso abertoS1678-77572010000500006-en.pdf00970316820636524517484241515548