How does a calcium phosphate-based biomimetic ceramic work as a direct pulp-capping agent?

Alternative calcium phosphate-based (CaP) bioceramics are currently being developed for direct pulp capping (DPC). These substances have the potential to minimize the adverse effects of certain cements while promoting reparative and regenerative processes. 

Aim: To compile available evidence of the biological processes triggered in the dentin-pulp complex when DPC is performed with CaP-based materials.

Methodology: A literature search was conducted between 2014-2024 in 20 databases published using "pulp capping" and "calcium phosphates". Articles involving bioceramics combined with metals, non-metals (e.g., fluorides), or polymers were excluded. 

Results: Eighteen articles were selected. Information was classified into three categories: a)Pulp repair, b)ionic activity and their role in dentin growth regulation, and c)the environment. It was evidenced that CaP materials stimulate the proliferation and differentiation of pulp stem cells and fibroblasts into odontoblast-like cells, as demonstrated by the expression of ALP, OCN, DSPP, and DMP-1. These cells express nestin and promote the development of mineralized nodules, leading to the formation of a dentinal bridge. Essential ions, including calcium, phosphorus, hydroxyl, and magnesium, play key roles in regulating cell proliferation and differentiation processes. They maintain a pH of 7.0-8.2, leading to better integration with surrounding tissues, while also enhancing biomineralization and apatite formation.  

Conclusion: CaP-based materials have been shown to stimulate the proliferation and differentiation of pulp stem cells into odontoblast-like cells, which are primarily responsible for pulp repair and regeneration. These materials also stimulate the creation of a favorable environment by supplying essential ions to regulate pH, modulate protein expressions, and promote dentin mineralization.