After pulp chamber trepanation, rubber dam and disinfection, tooth 47 was instrumented to size 60 (D) and 40 (MB and ML canals). The canals were constantly irrigated with 0.5 % sodium hypochlorite. At the end of the preparation the canals were irrigated with 17 % neutral EDTA, dried with large paper points and filled with calcium hydroxide. The tooth was sealed with IRM filling.