"A thorough understanding of the biology of the dentine-pulp complex is essential to underpin new regenerative treatments and maximise clinical impact within endodontics. After microbial or traumatic insult, the dentine-pulp will mount a complex response, with a balance between infection control, inflammation and host defence responses critical to determining tissue outcomes. Assessment of the regenerative capacity of the damaged pulp can be challenging as biomarkers of interest may exhibit functionality in both inflammation and repair. This balance is evident during reactionary and reparative tertiary dentinogenesis, which is driven by the release of bioactive dentine-matrix-components (DMCs) from the damaged dentine. DMCs contain a range of cytokines, chemokines and growth factors, which are released following injury and orchestrate the recruitment, migration, proliferation and differentiation of pulpal progenitor cells critical for the formation of newly deposited dentine. The field of Regenerative Endodontics embraces the repair, replacement and regeneration of dentine-pulp tissue and needs to combine basic pulp biology research aimed at understanding molecular interactions in the tooth as well as clinical therapies, such as vital pulp treatment, revitalization and stem cell-based therapies. This chapter discusses current views of the molecular and cellular processes underlying both reparative and regenerative responses in the dentine-pulp complex"-- Provided by publisher.