Magnesium Phosphate Cements for Endodontic Applications: A Critical Review of Promise and Pitfalls

Magnesium phosphate cements (MPCs) have recently gained attention as potential materials for endodontic applications due to their rapid setting, favourable mechanical properties, and bioactive potential. Laboratory and preclinical studies indicate that MPCs can form apatite-like structures, exhibit good compressive strength, and support cell viability, suggesting promising biological interactions. However, several limitations remain unresolved. The acid-base setting reaction of MPCs is strongly exothermic, which may pose a risk to pulp or periapical tissues, and ammonium-containing formulations can release cytotoxic ammonia, although partial mitigation is possible through sodium phosphate substitution. Rapid setting enhances handling in controlled conditions but may complicate placement in complex root canal anatomies. While in vitro studies suggest comparable or superior sealing ability relative to conventional calcium silicate cements, human clinical evidence is minimal or absent. Degradation and resorption profiles of MPCs may further affect their suitability as scaffolds in regenerative endodontics. Overall, MPCs represent promising investigational materials, yet claims regarding clinical readiness are premature. Careful evaluation of their physicochemical behaviour, biological safety, and practical handling is essential before consideration for routine clinical use.