The pulp chamber was trepanated with high-speed diamond bur and round burs at slow speed. The canals were located and the rubber dam was applied. The mesial root canals were then instrumented to size 45 each with manual instrumentation with NiTiflex/balanced force and H-files and constant irrigation with 0.5 % sodium hypochlorite. Smear layer was removed with 17% neutral EDTA and the canals were dried with nr. 40 paper points. The canals were filled with calcium hydroxide and sealed with Cavit-G and IRM.