Fig. 4

Toxdent performed using L929 cell line. All data are expressed as percent viability (least squares arithmetic means ± 95% confidence intervals), relative to values in the presence of the negative control (glass, 100% viability). Cytotoxic carboxylate cement (cem) was used as positive control, values above 70% viability (dashed line) were considered to confirm the absence of cytotoxic effects of the sample. Those 95% confidence intervals which do not cross the dotted line indicate significantly (p < 0.05) different mean values from 70%. Importantly, it was justified to also statistically estimate pooled mean values for horizontal and vertical samples, as there was no evidence for an effect of printing direction (p = 0.84)