EFFECT OF IRM ROOT END FILLINGS ON HEALING AFTER REPLANTATION

The effect of IRM as a root end filling placed in teeth prior to repla ntation was examined in 21 molar teeth in monkeys. After extraction, r oot ends were resected, the canals contaminated with oral bacteria, ro ot end cavities prepared, and fillings of IRM or amalgam placed prior to replantation. After 8 wk the jaws were removed and prepared for his tological examination. Bacteria were demonstrated in only 9 of 15 teet h filled with IRM; 18 of the roots (60%) were associated with inflamma tion, which was only moderate or severe around 5 (17%), and extended > 0.1 mm around only 2 roots. In contrast, of the 6 teeth filled with a malgam, all contained bacteria in the root canals and 11 roots were as sociated with moderate or severe inflammation, which around 8 roots ex tended > 0.5 mm. The difference in severity of inflammation for the tw o materials was statistically significant (p < 0.001). The tissue resp onse to root end fillings of IRM in replanted teeth was less severe an d less extensive than that to amalgam.