Related Experiment Videos
Interactions between neural and hydrodynamic mechanisms in dentine and pulp
1Department of Physiology, School of Medical Sciences, University of Bristol, England.
Archives of Oral Biology
|January 1, 1994
Summary
Fluid flow in dentinal tubules influences chemical diffusion into the pulp. Stimulating nerves in exposed dentine triggers protective reflex vasodilatation, reducing toxin entry.
Area of Science:
- Dentistry
- Physiology
- Biophysics
Background:
- Exposure of dentine allows inward diffusion of chemicals.
- Fluid dynamics within dentinal tubules play a role in pulp protection.
- Intradental nerves can be stimulated by hydrodynamic forces.
Purpose of the Study:
- To investigate the relationship between fluid flow in dentinal tubules and intradental nerve activity.
- To determine if reflex responses to dentine exposure can protect the pulp from chemical diffusion.
Main Methods:
- Demonstration of outward fluid flow through dentinal tubules in cats.
- Measurement of fluid flow rates under varying pulpal tissue-fluid pressure conditions (vasodilatation/vasoconstriction).
- Recording of intradental afferent nerve fiber discharge in response to controlled fluid flow.
Main Results:
- Outward fluid flow in dentinal tubules was demonstrated and found to be pressure-dependent.
- Pulp vasodilatation, induced by nerve stimulation, increased outward fluid flow.
- Intradental afferent nerves were more sensitive to outward than inward flow; excitation thresholds exceeded maximal vasodilatation flow rates.
Conclusions:
- Outward fluid flow in dentinal tubules modulates the rate of inward chemical diffusion.
- Stimulation of intradental afferent nerves by exposed dentine can initiate a protective reflex involving vasodilatation.
- This reflex reduces the diffusion of oral toxins into the pulp, offering a defense mechanism.