PULPAL RESPONSE TO MINERAL TRIOXIDE AGGREGATE (MTA) IN DECIDUOUS AND PERMANENT DENTITION - A REVIEW

Abstract

Mineral trioxide aggregate (MTA) is a calcium-silicate cement that reliably preserves pulp vitality in both primary and permanent teeth. On hydration, MTA releases calcium and hydroxyl ions, creating a sustained alkaline, antibacterial microenvironment that supports hemostasis, dampens acute inflammation, and liberates dentin growth factors (e.g., TGF-β). These signals drive odontoblast-like differentiation, laying a collagen scaffold that mineralizes into a continuous, often tubular dentin bridge formation. Clinically, this yields symptom resolution, maintained sensibility where appropriate, and radiographic evidence of a stable hard-tissue barrier with normal periapical/furcal outlines. In primary teeth, MTA pulpotomy demonstrates high success with fewer adverse sequelae than traditional agents. In permanent dentition, MTA performs predictably for direct/indirect pulp capping, partial pulpotomy, and apexogenesis, and serves as a dependable apical plug for apexification. Outcomes are seal-dependent and technique-sensitive, emphasizing meticulous hemostasis, isolation, and an immediate coronal seal. In primary teeth, the pulp typically shows rapid resolution of superficial inflammation, preservation of a healthy radicular pulp, and formation of a uniform dentin bridge with minimal internal resorption and physiologic exfoliation maintained. In immature permanent teeth, MTA fosters a mild, transient inflammatory phase followed by recruitment of odontoblast-like cells and stem/progenitor cells, enabling structured dentin bridge formation and continued root development (apexogenesis). In mature permanent teeth, the pulpal response is characterized by controlled hemostasis, a low-grade inflammatory infiltrate that subsides quickly, and deposition of a well-sealed mineralized barrier with few tunnel defects. Collectively, these tissue-level responses underpin the high clinical success of MTA across both primary and permanent dentitions.