Current Understanding and Future Applications in Dentine-Pulp Complex Inflammation and Repair

Infecting oral microorganisms, which penetrate through the tooth’s enamel and dentine, are responsible for dental caries. During the caries process, bacterial by-products reach the inner dentine and trigger host defence responses within the peripheral area of the dental pulp. If the diseased hard tissue is removed and the infection is resolved by the dental practitioner, the defence events regress and pulp healing can occur. Ideally for complete pulp healing, there should be formation, at the dentine-pulp interface, of a reactionary/reparative dentine layer which distances and protects the pulp from any invading bacteria and restorative material irritation. In its absence, chronic pulpal inflammation can endure despite treatment, and this can result in progressive damage of pulp tissue, as well as reduced innate repair capabilities. Clinical and laboratory studies indicate that dentine barrier formation only occurs when the pulpal inflammation is at a relatively low level, such as at the early stage of infection or when it is subsiding after clinical intervention. This chapter focusses on our current understanding of key cellular and molecular mechanisms which are involved in the pulp’s response to bacteria and how these responses modulate local inflammation and dentinogenic repair events. Subsequently the control of infection and modulation of pulp inflammation may provide novel therapeutic opportunities which can be harnessed by the dental practitioner in the future.