Nonsurgical Endodontics and Decompression-Based Management of Extensive Periapical Cystic-Like Lesions: A Comparative and Radiological Study with A Two-Year Follow-Up

<b>Background:</b> Large periapical cyst-like lesions pose challenges for nonsurgical management. This study evaluated the clinical and radiological outcomes of conventional endodontic therapy alone versus endodontic therapy with decompression in treating such lesions. <b>Methods:</b> Ten patients with CBCT-confirmed periapical lesions >5 mm were randomly assigned to two groups. Group 1 received standard root canal treatment with calcium hydroxide; Group 2 received the same protocol plus decompression. Lesion dimensions were measured in three planes using CBCT at baseline, 12 months, and 24 months. <b>Results:</b> Both groups showed significant lesion size reduction over time. At 12 months, Group 2 had a significantly greater mean reduction (8.49 ± 5.09 mm) compared to Group 1 (4.36 ± 1.46 mm) (<i>p</i> = 0.008). At 24 months, both groups had comparable outcomes (Group 1: 1.12 ± 0.98 mm; Group 2: 2.41 ± 5.15 mm; <i>p</i> = 0.356), with most lesions nearly or fully resolved. Histopathology confirmed radicular cysts in decompressed cases. <b>Conclusions:</b> Conservative endodontic therapy is effective for large periapical lesions. Adjunctive decompression accelerates early healing, particularly in extensive cases, potentially reducing the need for surgical intervention. CBCT is valuable for monitoring healing.