Removal Efficiency of Mineral Trioxide Aggregate: A narrative Review of Retrieval Techniques

Regenerative endodontic procedures are designed to eliminate clinical symptoms, promote periapical healing, and restore a functional pulp–dentin complex with continued root development. However, treatment failure may occur and require retreatment. In such situations, the removal of mineral trioxide aggregate (MTA) poses a significant clinical and technical challenge. This narrative review critically appraises recent advances in MTA removal techniques following failed regenerative endodontic therapy, with particular emphasis on removal efficiency, effects on radicular dentin, and subsequent management considerations. A systematic electronic search of PubMed and Google Scholar was conducted to identify English-language articles published between 2017 and 2025 using keywords related to regenerative endodontics, MTA retrieval, chemical solvents, and assessment methods. From an initial yield of 70 articles, 10 studies met the inclusion criteria based on relevance, methodology, and scientific merit. The available evidence indicates that complete removal of set MTA from the root canal system cannot be achieved using a single technique. Mechanical methods showed limited effectiveness, while ultrasonic activation enhanced MTA retrieval but consistently left residual material. Chemical agents, particularly acidic solutions, demonstrated superior MTA softening and removal potential. However, their application was associated with reduced dentin microhardness and signs of dentinal erosion, as confirmed by micro-CT and SEM analyses. In conclusion, the findings highlight the absence of a standardized and clinically optimal protocol for MTA removal and emphasize the need for further well-designed studies to establish safe exposure times, effective concentrations, and evidence-based guidelines that balance removal efficiency with preservation of radicular dentin integrity.