In-vitro and In-vivo Comparative Evaluation of Rotary Fanta and Zunba Files in Root Canal Preparation of Infected Primary Molars

Inclusion Criteria: * Class I or II according to American Society of Anesthesiologists (ASA) * Necrotic pulp tissues which may be asymptomatic or manifested with dull ache pain * Pathological tooth mobility * Percussion sensitivity * Swelling close to involved tooth accompanied with or without fistula * The extension of radiolucency at the furcation area did not exceed half of the space between the furcation and the permanent successor * No internal root resorption * External root resorption (Physiologic or pathologic) limited to apical third and with at least two-third root intact Exclusion Criteria: * Uncooperativeness of child and/or parents or caregiver's behavior. * Unrestorable tooth. * Presence of calcific metamorphosis inside root canals.