SHORT-TERM TISSUE-RESPONSE TO POTENTIAL ROOT-END FILLING MATERIALS ININFECTED ROOT CANALS

The short-term tissue responses to two potential root-end filling mate rials, a light-cured glass ionomer cement (Vitrebond) and a reinforced zinc oxide-eugenol cement (Kalzinol), were compared with that to amal gam using a previously devised experimental model. In 24 premolar teet h of beagle dogs (47 roots), a collection of endodontic pathogenic bac teria was first inoculated into the root canals to induce periradicula r lesions. On each root, an apicectomy was performed and root-end cavi ties prepared to receive fillings of each material, The teeth and surr ounding jaw were removed after 2 weeks (23 roots) and I week (24 roots ); they were then prepared for histological examination. The tissue re sponse to amalgam fillings after 2 weeks and I week was marked by mode rate or severe inflammation on all roots, and extended to less than or equal to 0.5 mm or >0.5 mm in IS out of 16 roots, In contrast, rafter 2 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 the least extensive, After 1 week, the overall best tissue response was with Vitrebond, followed b y Kalzinol. The differences between materials for both time periods wi th either none or few inflammatory cells when compared with that with either moderate or severe inflammation were not statistically signific ant (P<0.02). However, the differences between materials far both time periods with no inflammation or inflammation extending <0.2 mm when c ompared with that with inflammation extending >0.2 mm (less than or eq ual to 0.5 nun or >0.5 mm) were statistically significant (P<0.01), Ap art from amalgam, in which healing was marked by the persistence of a localized focus of inflammation adjacent to the root-end filling, even though there were intersample variations, there was little overall di fference in the temporal and qualitative healing response to Vitrebond and Kalzinol. Both Vitrebond and Kalzinol have potential as root-end filling materials, as the tissue response was considerably snore favou rable than that to amalgam even in the short-term.