What is dental pulp?
Unique vital connective tissue within the root canal system.
What are periapical tissues?
Vital tissues surrounding the root apex.
How is the dental pulp connected to the periapical tissues?
Via the apical foramen, lateral/accessory canals, apical delta
What are the primary functions of dental pulp?
- Related to tooth formation
- Induction: including epithelial-mesenchymal interactions, induces differentiation of
odontoblasts/ameloblasts - Formation: odontoblasts form dentine and ameloblasts form enamel
What are the secondary functions of dental pulp?
- Related to support during tooth development and maintenance of health and vitality of the tooth
- Nutritive
- Sensory: proprioception, nerves respond to stimuli
- Defence: protective and reparative, immune and inflammatory responses
What are the components of dental pulp?
- Cellular
2. Extracellular component
What components make up the extracellular component?
- Fibres
- Ground substance
- Blood vessels
- Lymphatics
- Nerves
Organisation of the dental pulp
- Odontoblast layer
- Sub-odontoblast layer
- Pulp proper
Features of the odontoblast layer
- Sub-adjacent to dentine
- Contains odontoblastic cell bodies
- Morphology of odontoblasts reflects function
- Terminally differentiated cells
- New odontoblasts may differentiate from pluripotent cells from the sub-odontoblast layer
Features of the sub-odontoblast layer
- Contains a cell free zone which is beneath the odontoblast later - contains processes of fibroblasts, blood vessels and nerves
- Also contains an underlying cell-rich zone which contains many undifferentiated cells, fibroblasts, immune cells, blood vessels and nerves
Types of pulp proper
- Parietal and Central pulp
Features of the parietal pulp
- Smaller blood vessels and nerve fibres
Features of the central pulp
- Major blood vessels and verve fibres
- Fibroblasts
- Defence cells
- Collagen
- Dental Pulp Stem cells (DPSCs)
Cells of the dental pulp
- Odontoblasts
- Fibroblasts - most numerous
- Undifferentiated stem cells
- Defence cells (macrophages, lymphocytes, pulp dendritic cells)
Function of fibroblasts
Produce collagen and ground substance.
Also involved in collagen degeneration and turnover
What are the age-related change of fibroblasts?
Young fibroblast: plump nucleus, stellate-shaped, prominent protein synthesis
Old: condensed nucleus, flattened
Features of undifferentiated mesenchymal stem cells
- Mainly found in the cell rich zone and throughout pulp
- Pluripotent and primitive
- Migrate and differentiate into odontoblasts in response to cell injury/death
What is the most predominant immune cell of the pulp?
What is the most predominant immune cell of the pulp?
