Cost-effectiveness of tooth preservation versus implant for persistent periapical pathosis in mandibular second molars

INTRODUCTION: Persistent apical periodontitis in mandibular second molars presents a clinical decision between tooth preservation and extraction with implant replacement. Although intentional replantation (IR), surgical endodontic treatment, and implant therapy demonstrate acceptable outcomes, their long-term economic value remains unclear. This study evaluated the cost-effectiveness of tooth-preserving strategies versus extraction with implant placement. MATERIALS AND METHODS: A Markov model simulated 40-year-old patients with persistent apical periodontitis in a mandibular second molar from a United States (US) private payer perspective. Three strategies were compared: IR, surgical endodontic treatment, and extraction with implant placement. The model used 6-month half cycles over 39.3 years with 3% annual discount rate. Transition probabilities were derived from systematic reviews and clinical studies. Costs were obtained from the American Dental Association (ADA) 2022 survey adjusted to 2025 USD. Effectiveness was expressed as retained tooth-years or implant-years. Deterministic and probabilistic sensitivity analyses using 10,000 Monte Carlo simulations assessed uncertainty. RESULTS: IR yielded 16.09 retained tooth-years at USD 2,676. Surgical endodontic treatment provided an additional 0.32 years corresponding to 16.41 tooth-years at an Incremental Cost-Effectiveness Ratio (ICER) of USD 4,279.66. Extraction with implant placement achieved 19.08 implant-years at an ICER of USD 580.60. Probabilistic analysis showed IR was cost-effective at lower willingness-to-pay thresholds, whereas implant placement became preferred beyond approximately USD 600. CONCLUSION: In mandibular second molars with persistent apical periodontitis, IR proved economically favorable in the short-term, while extraction with implant placement offered superior long-term effectiveness at reasonable incremental costs for patients with extended life expectancy.