Long-Term Clinical and Radiographic Outcomes of Large Periapical Lesions Managed by Non-Surgical and Surgical Endodontic Treatment: A Case Series.

The management of large periapical lesions is challenging, as lesion size alone does not predict treatment outcome or mandate surgery. This case series presents three large periapical lesions with 4- to 12-year follow-up, illustrating different therapeutic pathways. Two cases (mandibular canine/premolar and maxillary lateral incisor) resolved with non-surgical treatment, achieving radiographic healing at 12-year and 5-year follow-ups, respectively; the lesion in Case 1 persisted at 2 years but resolved by 12 years. The third case (maxillary lateral incisor with sinus tract and swelling) failed non-surgical retreatment, requiring periradicular surgery with MTA, resulting in complete healing at 4 years. All cases achieved Periapical Index scores of 2. This series demonstrates that non-surgical management remains first-line, but persistent symptoms, sinus tracts, or lack of radiographic improvement at 1 year should prompt surgery. Long-term follow-up is essential to distinguish delayed healing from true failure.