TISSUE-RESPONSE TO POTENTIAL ROOT-END FILLING MATERIALS IN INFECTED ROOT CANALS

The tissue responses to two potential root-end filling materials, a li ght-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide -eugenol cement (Kalzinol) were compared with that to amalgam. In 27 p remolar teeth of beagle dogs (54 roots), a collection of endodontic pa thogenic bacteria was first inoculated into the root canals to induce periapical lesions. On each root, an apicectomy was performed and root -end cavities prepared to receive fillings of each material. The teeth and surrounding law were removed after 8 weeks (24 roots) and 4 weeks (30 roots); and they were prepared for histological examination, The tissue response to amalgam fillings after 4 and 8 weeks was marked by moderate or severe inflammation on all roots, and extended > 0.5 mm in 10 out of 18 roots. In contrast, after 8 weeks, the majority of roots filled with Kalzinol showed little or moderate inflammation while the tissue response to Vitrebond was the best of the three materials, and was also less extensive. After 4 weeks, the overall best tissue respo nse was with Kalzinol, followed closely by Vitrebond, The differences between materials for both time periods with either none or few inflam matory cells when compared with that with either moderate or severe in flammation were statistically significant (P<0.01), Similarly, the dif ferences between materials for both time periods with no inflammation or inflammation extending <0.2 mm when compared with that with inflamm ation extending >0.2 mm (less than or equal to 0.5 mm or >0.5 mm) were statistically significant (P<0.01), Both Vitrebond and Kalzinol have potential as root-end filling materials as the tissue response was con siderably more favourable than that to amalgam.