Can A Large Apical Leison Case Treated by Non-surgical Root Canal Retreatment?

Background of this case: A 40 year-old male patient was referred to further treatment of tooth 16 due to persistent swelling and pain after tooth 16 root canal treatment was done for 1 year. Pre-op x-ray and CBCT was checked, tooth 16 MB2 canal was left untreated and a 2 cm* 2 cm apical lesion was noted around teeth 16 17 apical region. Tooth 17 responded to pulp vitality test. Dx: Tooth 16 previously treated/ chronic apical abscess Treatment Plan: 1. Tooth 16 non-surgical root canal retreatment first (If any s/s persist, then apical surgery will be indicated)2. Keep monitoring tooth 17 pulp vitality Treatment Procedures of tooth 16 : Removed old restoration, old filling materials and located MB2 canal…