dentine and pulp complex Flashcards
(37 cards)
what is found in dental pulp?
- cells
> odontoblasts
> fibroblasts
> defence cells
- extracellular components > fibres ~ collagen ~ oxytalan > matrix ~ proteoglycans ~ chondroitin ~ dermatan
- nerves
> sensory, autonomic - blood vessels
- lymphatics
name the layers of dentine-pulp complex
dentine predentine odontoblasts cell free zone cell rich zone
what are the functions of the dental pulp?
- nutritive (blood vessels)
- dentine growth / physiological growth
> primary
> secondary - dentine repair
> tertiary - defence
> immune cells
> lymphatics - neural
> sensory
~ pain
> control of dentinogenesis
what are the developmental links between dentine and pulp?
dentine and pulp develop from the dental papilla
what are the structural links between dentine and pulp?
- pulpal elements extend into dentine > odontoblast processes > nerve terminals > immune cells (dendritic cells) > dentinal fluid [note there are no blood vessels in normal dentine]
what are haemodynamics?
the dynamics of blood flow
what are hydrodynamics?
the branch of science concerned with forces acting on or exerted by fluids (especially liquids)
where does the fluid that leaks from the pulp capillaries go?
interstitial space
what are the ways in which this fluid can leak?
some drains by lymphatics
some passes along dentinal tubules
{look at diagram in lecture maybe for explanation on the outward tubular fluid flow}
what is the dentinal fluid flow proportional to?
pulp pressure
what are the functional links between dentine and pulp?
- formation of secondary dentine
- formation of tertiary dentine in response to tooth wear
> reactionary dentine
> reparative dentine - regulate exchange of material between dentine and pulp
name 6 things that cause tooth wear
- mastication / abrasion
- bruxism / attrition
- abfraction / occlusal overload
- diet = erosion
- caries
- operative procedures (cavity cutting and crown prep)
define abrasion
the process of scraping or wearing something away
define bruxism
involuntary habitual grinding of the teeth, typically during sleep
define attrition
the process of reducing something’s strength or effectiveness through sustained attack or pressure
define abfraction
is the mechanical loss of tooth structure that is not caused by tooth decay, located along the gum line
what are the 2 types of tertiary dentine
reactionary
reparative
what is reactionary dentine
it is laid down in response to a mild stimulus
laid down by primary odontoblasts
what is reparative dentine
it is laid down in response to a severe stimulus which destroys the primary odontoblasts
laid down by secondary odontoblasts
explain the odontoblast layer as a permeability barrier
separates pulp and tubular space
Regulates movement of material between pulp and tubular ECF, Movement can be in either direction
what material is exchanged from the pulp to the dentine
- nutrients
- formation of secondary and tertiary dentine
- function of tubular nerves eg potassium for membrane potential
what material is exchanged from the dentine to the pulp
- medicaments applied to dentine
- diffusion of toxins from bacteria
- diffusion of components from filling materials
what is the anatomy of pulp nerves
branches of alveolar nerves
- neurovascular bundles enter pulp via apical foramen
- pass along root canal in centre of pulp towards coronal pulp chamber
- branches fan out in sub-odontoblastic layer = Raschow’s plexus
- terminal branches enter odontoblast layer, some nerves enter dentinal tubules
explain the innervation of dentine
some nerves enter dentine - Under cusps ○ 40% of tubules contain nerves ○ Some axons extend around 100-200 micrometres - Coronal dentine ○ Less; around 15% - Root dentine ○ As little as 4% Few axons enter tubules, most end in pre-dentine region
