SEALING ABILITY OF POTENTIAL RETROGRADE ROOT FILLING MATERIALS

The sealing ability of two potential retrograde root filling materials , a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol) was compared with that of amalgam usi ng three methods of assessment: bacterial leakage, confocal microscopy and Indian ink leakage. The root canals of 80 extracted human single- rooted teeth were prepared. All the teeth were apicected, retrograde c avities were prepared and then divided into four equal groups of 20 te eth. The teeth were sterilised by autoclaving and the retrograde cavit ies filled with the test materials. In the control group, retrograde c avities in 10 teeth were left unfilled while cavities in another 10 te eth were sealed with cyanoacrylate cement. The teeth were first subjec ted to a bacterial leakage test using Enteroccocus faecalis as a leaka ge marker. After which, the adaptation of the retrograde root fillings was assessed using a confocal optical microscope. Finally, the teeth were processed for the Indian ink leakage test. Bacterial leakage occu rred in more teeth filled with amalgam compared with both Vitrebond an d Kalzinol (P<0.001), between which there were no differences. With co nfocal microscopy, the size of the marginal gap was largest with amalg am and smallest with Vitrebond; all differences were statistically sig nificant (P<0.001). Finally, there was more Indian ink penetration wit h amalgam compared with both Vitrebond and Kalzinol(P<0.001) but there were no differences between Vitrebond and Kalzinol. Although there we re individual differences within samples, overall, the three methods o f assessment produced similar results. The sealing ability of Vitrebon d and Kalzinol was similar and both materials were better than amalgam .