Nanostructured hydroxyapatite as filler for methacrylate-based root canal sealers.

To evaluate the effect of different concentrations of nanostructured hydroxyapatite on the radiopacity, flow and film thickness of an experimental root canal sealer. An experimental dual-cured root canal sealer was produced with a methacrylate-based co-monomer blend. Nanostructured hydroxyapatite/calcium tungstate solutions (ratios 10:90, 20:80, 30:70 and 40:60) were added to produce the sealer. Radiopacity was evaluated using a digital system and an aluminium step wedge (n=5). Flow and thickness tests were conducted in accordance with ISO 6876 (n=3). The data were analysed using one-way anova and Tukey's test (α=0.05). All groups had levels of radiopacity in accordance with ISO 6876. The flow of the experimental sealers was not significantly different (P=0.204). All groups had a film thickness in accordance with ISO 6876 and with no statistical difference (P = 0.654). The addition of up to 40% HA(nano) to root canal sealers did not alter their radiopacity and film thickness.