Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

Author(s)

Fabio Aranha, Andreza Maria ^[1] ; Aparecida Giro, Elisa Maria ^[2] ; Hebling, Josimeri ^[2] ; Rosetti Lessa, Fernanda Campos ^[3] ; de Souza Costa, Carlos Alberto ^[4]

Affiliation

^[1] Univ Sao Paulo, Bauru Sch Dent, Dept Biol Sci, Bauru, SP - Brazil

^[2] Sao Paulo State Univ, Araraquara Dent Sch, Dept Orthodont & Pediat Dent, Discipline Pediat Dent, Araraquara, SP - Brazil

^[3] Vila Velha Univ Ctr, Discipline Pathol, Vitoria, ES - Brazil

^[4] Sao Paulo State Univ, Araraquara Dent Sch, Discipline Pathol, Dept Physiol & Pathol, Araraquara, SP - Brazil

• Document type: Journal article
• Source: Journal of Applied Oral Science; v. 18, n. 5, p. 461-466, SEP-OCT 2010.
• Web of Science Citations: 18

Abstract

This 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 µL 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/cm²) were plated and incubated in a humidified incubator with 5% CO2 and 95% air at 37ºC 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. (AU)

• FAPESP's process: 08/08424-6 - Direct and transdentinal effects of 660 nm led irradiation on odontoblast-like cells
• Grantee: Carlos Alberto de Souza Costa
• Support Opportunities: Regular Research Grants