Background
inflammation, enlargement
INFLAMMATION, ENLARGEMENT
Success in non-surgical retreatment is the removal of the contaminated previous root canal filling followed by the re-shaping, disinfection and finally hermetic filling of the root canals. Mechanical enlargement is not sufficient for widening and cleaning root canals because of the inability to make contact with all the dentin walls. Chemomechanical preparation is needed for many reasons, such as debris removal, canal disinfection, and lubricant effects during root canal treatment [Manual dynamic activation (MDA), passive ultrasonic irrigation (PUI), and sonic irrigation (SI) are the most frequently used activation techniques [These activation methods and preparation techniques have been found to cause inflammation in the periapical tissues. A certain amount of debris is extruded from the apical during the preparation for or removal of a root canal filling [