Nonsurgical Retreatment of a 16 × 9 mm Osteolytic Lesion With Buccal Bone Regeneration Using a Bioceramic Sealer: A Clinical and NGS‐Based Microbiological Case Report With 30‐Month Follow‐Up

This case report described the complete resolution of a large osteolytic lesion following a nonsurgical endodontic retreatment using a premixed bioceramic sealer. A 30-year-old healthy patient presented a large radiographic osteolytic lesion of 16 × 9 mm in correspondence with Teeth #42, #41, and #31. Clinical examinations revealed positive percussion tests and increased mobility of all incisors. The microbiological profile of the root canals was assessed through paper point sample collection, DNA extraction, and next-generation sequencing, revealing markedly different proportions of bacteria genera in the affected teeth. A secondary endodontic treatment was then performed, combining manual, rotary, and reciprocating protocols. A premixed bioceramic-based sealer (CeraSeal) was used for obturation due to the presence of wide and wet apexes. Radiographic (x-rays and CBCT) and clinical evaluations reported the progressive healing of the lesion over 30 months. This outcome supports the use of conservative treatments as a valid alternative to endodontic surgery for the management of extensive periapical lesions.