Presentation on theme: "Pulpal Pathogenesis Caroline G. Ayoub. Outline Contents of the healthy pulp Etiology of pulpal disease Immunological shift from health to disease."— Presentation transcript:
Pulpal Pathogenesis Caroline G. Ayoub
Outline Contents of the healthy pulp Etiology of pulpal disease Immunological shift from health to disease Take home points
Odontoblast Dentin formation Main source of TGF-b Innate Immunity
Fibroblast Most numerous cells of the pulp Abundant in the cell-rich zone Synthesize types I and III collagen Have capacity to produce pro-inflammatory cytokines in response to PAMPs.
Immunocompetent Cells Lymphocytes T lymphocytes: normal residents of human dental pulp CD8+ outnumber CD4+ T lymphocytes in the dental pulp Macrophages Primary function: Phagocytosis Antigen presentation via expression of Cl II MHC molecules on their surface Dendritic Cells Peculiar dendritic morphology High motility Limited phagocytic activity Expression of high amounts of Cl II MHC molecules Potent capacity for antigen presentation to T lymphocytes
Nerves PAIN A delta fibers C fibers Secondary dentin Dental pulp is among the most densely innervated tissues in the body
Etiology Bacteria Trauma Orthodontic Tx
A schematic illustration of dental pulp responses to dental caries from Japanese Dental Science ReviewJapanese Dental Science Review Health to Disease
How do pulp cells react to the insult? Odontoblasts: Host defense activated Fibroblasts: Inflammatory mediators produced Macrophages: APC Dendritic Cells: APC Lymphocytes: T cells recognize MHC on APC
In other words…
What about the Nerves?
Neuropeptides The largest class of neurotransmitters/neuromodulators Possess multiple recognition sites for receptor binding Cannot cross cell membranes: Target cells need to have receptors and binding sites Examples include: Substance P (SP) Calcitonin Gene-Related Peptide (CGRP)
Substance P In the central pulp, SP fibers traverse in close proximity to blood vessels. In the periphery, many SP fibers are directly associated with small blood vessels SP fibers are also observed at the subodontoblast layer where they branch toward predentin, with some SP fibers penetrating into the dentin
CGRP Branch extensively in the coronal pulp near the pulp horn tip and enter into dentin for up to 0.1 mm Multiple studies have demonstrated that trigeminal afferent neurons expressing CGRP innervate dental pulp The existence of high-affinity binding sites for CGRP has been reported in the dental pulp as well as other tissues in the body.
So… Two dynamic changes occur to afferent neurons during inflammation: 1 st there is a sprouting of afferent fibers 2 nd local increases in inflammatory mediators trigger neuropeptide release Neurogenic inflammation
Take Home Points Innate Immunity Adaptive Immunity Neurogenic Inflammation