Figure 4. Effect of TEGDMA on the viability of fibroblasts. The viability of gingival fibroblasts treated with various concentrations of TEGDMA for 24 hrs was determined by the MTT assay. Each result represents the TEGDMA TD₅₀ value obtained with cells expressing GSTP1 *A/*A (n = 9), *A/*B (n = 9), and *B/*B (n = 5). *Indicates a significant difference between the *B/*B and *A/*A groups (P < 0.05). The mean values are indicated by dashes.