Single-file Pulpectomy in Primary Molars

Inclusion Criteria: * Children categorized as class I or II according to American Society of Anesthesiologists (ASA). * Children aged between 4 and 6 years with at least one necrotic primary second mandibular molar. * History of dull toothache over an extended period of time * History of spontaneous pain or pain at night * Swelling adjacent to tooth with or without a sinus tract * Abnormal tooth mobility * Presence of necrotic pulp tissue or purulent discharge when the pulp chamber was accessed * Interruption of lamina dura or thickening of periodontal ligament space * Furcational radiolucency did not surpass half of the distance between the furcation and permanent successor * Negative findings of internal root resorption * External root resorption confined to the apical third and with at least two-thirds of the root length was intact Exclusion Criteria: * Uncoperative children or parents/legal guardians * Sever intellectual, behaviour or emotional problems * Non-restorable tooth crowns * Root canal obliteration * Presence of underlying dentigerous or follicular cysts