pulp and dentine Flashcards
What type of connective tissue is pulp
Loose connective tissue (viscous gel like substance)
Innervation of pulp
Sensory (somatic Afferents)
Autonomic (sympathetic)
5 functions of pulp
Nutrition (blood)
Immune defence
Growth of dentine pri and sec
Repair of dentine tertiary
Pain transmission (sensory)
How is dentinal fluid formed
Leakage of fluid from pulp capillaries
What’s the difference between between reactionary and reparative dentine
Reactionary - odontoblasts
Reparative - more severe, odontoblasts dead so replaced by differentiated sub-odontoblastic stem cells
Plexus of raschow location
Below the cell rich layer
Which cranial nerve innervates pulp
Trigeminal division 2 and 3 (maxillary and mandibular
Dentinal tubules in which location has the highest chance of finding nerves
40% of cuspal dentine has nerves
15% of coronal dentine has nerves
4% of root dentine has nevees
Inward or outward flow activates interdental nerves more?
Outwards because of the pressure stretching the nerves causing greater stimuli
Type of collagen in pulp
Type 1 and 3
Oxytalan
Does pulp have lymphatics
Yes
What pulpal elements extend into dentine?
Odontoblast processes
Dentinal fluid
Immune cells
Nerve terminals
Relationship between dentinal flow and pulp pressure
Proportional
How does outward dentinal tubules fluid flow have a defence function?
Outwards flow temporarily keeps bacteria and harmful substances away from the pulp until other immune mechanisms step in
6 causes of toothwear
Attrition
Erosion
Abrasion
Abfraction
Caries
Operative procedures
How does tertiary dentine protect the pulp
Forms a plug and seals off dentinal tubules from the pulp
What is a way to treat hypersensitivity
Potassium nitrate depolarizes nerves and prevents Repolarisation
Some other chemical agents also plug dentinal tubules preventing outward flow of dentinal fluid
Is cooling and heating outward or inward flow of dentinal fluid
Cooling- outwards
Heating inwards
Think about cold and hypersensitivity - more activation of nerves so outwards stretching of nerves
How does high fillings cause dentinal pain?
Force distorts the dentine and alters fluid flow
Blood supply of teeth
External carotid -> maxillary artery -> superior alveolar artery and incisive artery (mandibular)
Why is permeability of inner dentine higher than that of outer dentine
Inner dentine has more tubules and tubules of larger diameter
Types of nerve fibres in pulp
A beta
A delta
C fibres
Most of the fibres inside the pulp are the tapered terminal segments of axons
Are majority of the nerve fibres in pulp sensory or sympathetic nerves?
Sensory - pain
What is the hydrodynamic mechanism of dentinal fluid
1 stimulus acts on exposed dentine
2 increases dentinal fluid flow
3stretches the intradental nerves and generates AP
4sends signal to brain to cause pain
How is blood supply in pulp controlled
Vasoconstriction - sympathetic nervous system
Vasodilation - peptides released by peptidergic sensory afferents ( CGRP AND SUB P are potent vasodilators)
Adrenaline - hormone vasoconstriction
Dugs like local anaesthetic (vasoconstriction )
Describe the process of neurogenic inflammation
Stimulation
Sensory nerve activation
Release of peptides CGRP and sub p
Vasodilation causing increased permeability of blood vessels
Influx of immune and exudate
Increased pulpal pressure and outward tubular fluid flow
More nerve activation
