Pulp Flashcards
What are 5` functions of dental pulp?
- Inductive - Initiates tooth formation
- Formative - Odontoblasts surround pulp
- Protective - Responds to stimuli
- Nutritive - Carries oxygen and nutrients to tooth
- Reparative - Formation of tertiary dentin
What tissue type is the dental pulp?
Specialised loose CT
Where is the dental pulp derived from?
Dental papilla
Where is dental pulp found?
Pulp chamber and root canals of the tooth
What are the 2 anatomical regions of the pulp?
- Coronal Pulp
2. Radicular Pulp
Where is the coronal pulp found?
The crown of the tooth
What are the 6 surfaces of the coronal pulp?
- Mesial
- Distal
- Buccal
- Lingual
- Occlusal
- Floor
Where is radicular pulp found?
Root of the tooth
From the outermost layer to the innermost layer, what are the 4 histological zones of the dental pulp?
- Odontoblastic zone
- Cell-free zone
- Cell-rich zone
- Pulp core
Name 4 cell types found in the pulp
- Odontoblasts
- Fibroblasts
- Undifferentiated mesenchymal cells
- Defence cells
What is the function of fibroblasts?
Make the matrix components of pulp i.e. fibres and ground substance
Where are fibroblasts found?
Cell-rich zone
What is the function of undifferentiated mesenchymal cells?
Pools of cells from which new odontoblasts or fibroblasts can be derived
What are 4 components of the pulp matrix?
- Fibres
- Glycosaminoglycans
- Proteoglycans
- Glycoproteins
What 2 things make up the fibres found in the pulp matrix?
- Collagen Type I
2. Collagen Type II
Name 3 GAGs found in the pulp matrix?
- Hyaluronic acid
- Dermatan sulphate
- Chondroitin sulphate
What are proteoglycans?
Protein core and a GAG
What are the 3 levels of vascular supply to the pulp?
- External carotid arteries
- Superior and inferior alveolar arteries
- Pulpal arterioles
Where are most of the nerve ends found in the dental pulp?
Odontoblasts, cell-free zone or dentinal tubules
What is the nerve plexus of the crown found beneath the odontoblasts?
Plexus of Raschkow
What are 4 ways hypersensitivity of the pulp can be triggered?
- Temperature
- Mechanical pressure
- Chemical exposure
- Dehydration
What were the 3 theories put forward to explain sensitivity?
- Direct innervation
- Transduction
- Hydrodynamic
What is the direct innervation theory?
Nerve fibres extend through entire dentinal tubule and directly transmit pain
What is the transduction theory?
Odontoblasts act as receptors for pain and transmit signal to nerves
Why is the direct innervation theory wrong?
Plexus of Raschkow is not mature until complete tooth eruption
Why is the transduction theory wrong?
No synapse is found between odontoblasts and nerves
What is the hydrodynamic theory?
Stimuli cause movement of dentinal fluid which causes depolarisation of nerve endings at dentin-pulp interface
How does cold and chemical stimuli cause dentinal fluid to move?
Outward flow of fluid
How does mechanical and hot stimuli cause dentinal fluid to move?
Inward flow of fluid
What are 4 age-related changes to pulp?
- Pulp is small
- Pulp is less vascular
- Pulp is more fibrous
- Pulp is less innervated
What are pulp stones?
Round calcified masses which appear in root canal or coronal portions of pulp
What is the main cause of pulp stones?
Aging
What are 2 types of pulp stones?
- True denticles
2. False denticles
What does a true denticle resemble?
Dentin
What does a false denticle resemble?
Bone
What are 3 major clinical considerations with regards to dental pulp?
- Pain from other sites can radiate to here e.g. angina
- It is sensory so requires anaesthesia during cavity preparation
- Pain in pulp is difficult to localise
