Lesion Sterilization and Tissue Repair (LSTR) Approach for Delaying Tooth Extraction: A Case Report

Primary teeth may present with periradicular lesions too advanced to be managed by conventional endodontic treatment. Recent studies have shown that the Lesion Sterilization and Tissue Repair (LSTR) approach using triple-antibiotic pastes effectively eliminates root canal bacteria. This supports host immune-mediated tissue repair, thereby delaying tooth extraction. A six-year-old uncooperative girl presented with pain in mandibular primary molars 74 and 85, showing cavitated lesions, a buccal abscess, furcation involvement, distal root resorption in 74, and internal resorption in both mesial roots. Diagnosed with pulpal necrosis and chronic periapical periodontitis, LSTR therapy was applied after the family declined extraction under general anesthesia. Pain resolved by one month, lesions decreased with intermittent pain at three months, chronic pain fully resolved by six months, and at one year, sinus tract formation and advanced root resorption were noted, though the patient remained asymptomatic; follow-up continues. LSTR therapy is a practical interim option for retaining primary teeth otherwise indicated for extraction, though further studies are needed to clarify its long-term outcomes.