Cytotoxicity of Several Materials on Human Dental Pulp Fibroblasts

Objectives: The aim of this in vitro study was to evaluate the cytotoxicity of different dental materials applied to human dental pulp fibroblasts. Methods: Third molar pulp was collected and cultured in DMEM. Cells (50,000 cells/cm²) were plated in 24-well plates and incubated in a humidified incubator at 37^oC with 5% CO₂ and 95% air until reach confluence. Solid and fluid materials were employed: Group 1(G1)- Single Bond(3M ESPE), G2-Vitrebond(3M ESPE), G3-Ketac Molar(3M ESPE), G4-Dycal(Dentsply) were applied as round shaped specimens (2mm thick and 5mm in diameter) prepared according to the respective manufacturer's instructions into transwell membranes. G5-HEMA 10nM, G6-HEMA 100nM, G7-HEMA 1000nM, G8-Single Bond unpolymerized in the concentrations of 1:100; G9-1:1,000 and G10-1:10,000 were added to the culture medium. G11-control group (medium alone) and G12-control group (transwell alone) were also evaluated. The cytotoxicity analysis was performed using Trypan Blue dye exclusion and methyltetrazolium assay for mitochondrial respiration (MTT assay) at times of 6 and 24 hours. The data were compared by ANOVA (p<0.05) and Tukey's post hoc test (p<0.05). Results: The cell viability in the Trypan Blue assay was G1:92.81%; G2:92,03%; G3:88,85%; G4:90,14%; G5:94,92%; G6:92,49%; G7:93,89%; G8:92,70%; G9:86,25%; G10:40%; G11:93,38% and G12:91,25% at 6 hours. At 24 hours the cell viability was G1:86,56%; G2:65,43%; G3:84,43%; G4:6,45%; G5:89,72%; G6:90,15%; G7:89,81%; G8:87,64%; G9:75,30%; G10:4,54%; G11:87,50% and G12:87,79%. The MTT assay demonstrated the following results: G1:99,41%; G2:95,89%; G3:96,48%; G4:96,48%; G5:127,52%; G6:126,48%; G7:125,78%; G8:125,08%; G9:139,02%; G10:81,88%; G11:100,00% and G12:100,00% at 6 hours. At 24 hours the MTT assay was G1:102,83%; G2:95,89%; G3:96,48%; G4:96,48%; G5:127,52%; G6:126,48%; G7:125,78%; G8:125,08%; G9:139,02%; G10:81,88%; G11:100,00% and G12:100,00%. Conclusion: G2, G3, G4, G8, G9 and G10 presented the most cytotoxic effects while G5, G6 and G7 increased the cellular metabolism of the cultured fibroblasts. The events related with the increase in the metabolism should be investigated.