The role of inflammation modulation in dental pulp regeneration

A vital and healthy dental pulp (DP) is required for teeth to remain functional throughout a lifespan. Appreciating its value for the tooth, the regeneration of the DP is a highly researched goal. While inflammation of the DP marks the beginning of an eventual necrosis, it is also the prerequisite for the regenerative events of neovascularisation, stem cell mobilisation and reparative dentine deposition. In the light of a pro-regenerative inflammatory process, the present review discusses the role of the macrophage population shift from pro- to anti-inflammatory in reversible versus irreversible pulpitis, while also analysing the overlooked contribution of pulp innervation and locally derived neuropeptides to the process. Then, the currently practiced (pulp capping and revascularisation) and researched (cell transplantation and cell homing) approaches for DP regeneration are discussed. Focusing on the role of cell homing in modulating inflammation, some potential strategies are highlighted to harness the inflammatory process for DP regeneration, mainly by reversing inflammation through macrophage induction. Next, some potential clinical applications are discussed - especially with capping materials - that could boost macrophage polarisation and complement system activation. Finally, current challenges facing the regeneration of the DP are presented, while underlining the importance of promoting an anti-inflammatory environment conducive to a regenerative process.