The cytotoxicity of potential retrograde root-filling materials was as
sessed using the Millipore filter method. A light-cured glass ionomer
cement, Vitrebond (VB), and three reinforced zinc oxide-eugenol cement
s, Kalzinol, IRM and ethoxybenzoic acid (EBA) cement, were compared wi
th amalgam. Twenty standardized pellets of each material, 10 fresh and
10 aged by storage in sterile distilled water for 72 h were produced.
Ten filters were included as controls: five filters with a cell monol
ayer, but without test specimens, and another five without cells but w
ith test specimens. Fresh IRM exhibited the most pronounced cytotoxic
effect and the difference was statistically significant compared with
all the other materials. There was no statistically significant differ
ence between fresh VB, Kalzinol, EBA cement and amalgam. When aged, Ka
lzinol was the most cytotoxic and the difference was statistically sig
nificant compared with the other materials. Aged IRM was the second mo
st cytotoxic material and this too was statistically different. The cy
totoxicity of VB, EBA, and amalgam did not differ significantly from o
ne another.