The use of 4 per cent sodium hypochlorite, with or without ultrasound, in cleansing of uninstrumented immature root canals; SEM study

Barbed broaches were used to remove the intact pulp from freshly extracted, single rooted, human first bicuspid teeth with an immature apex. The efficiency of 4 per cent sodium hypochlorite in the removal of soft tissue and predentine from the root canal wall was assessed using the scanning electron microscope. Four per cent sodium hypochlorite was found to be an efficient protein solvent in these wide canals, and this efficiency was increased by using ultrasound to activate the sodium hypochlorite solution. After 3 minutes exposure to the 4 per cent sodium hypochlorite/ultrasound combination, the root canal surface was free from pulpal debris and predentine. The presence of calcospherites on the root canal wall indicated that the debridement had been achieved without the loss of any of the calcified root canal wall thickness.