Advances in Dental Research, Vol 9, 235-238, Copyright © 1995 by International & American Associations for Dental Research
Role of saliva in caries models
W. M. Edgar and S. M. Higham
The University of Liverpool School of Dentistry, Department of Clinical Dental Sciences, UK.
The crucial role played by the actions of saliva in controlling the
equilibrium between de- and remineralization in a cariogenic environment is
demonstrated by the effects on caries incidence of salivary dysfunction and
by the distribution of sites of caries predilection to those were salivary
effects are restricted. However, of the several properties of saliva which
may confer protective effects, it is not certain which are most important.
A distinction can be made between static protective effects, which act
continuously, and dynamic effects, which act during the time-course of the
Stephan curve. Evidence implicates salivary buffering and sugar clearance
as important dynamic effects of saliva to prevent demineralization; of
these, the buffering of plaque acids may predominate. Enhanced
remineralization of white spot lesions may also be regarded as dynamic
protective effects of saliva. Fluoride in saliva (from dentifrices,
ingesta, etc.) may promote remineralization and (especially fluoride in
plaque) inhibit demineralization. The design of experiments using caries
models must take into account the static and dynamic effects of saliva.
Some models admit a full expression of these effects, while others may
exclude them, restricting the range of investigations possible. The
possibility is raised that protective effects of saliva and therapeutic
agents may act cooperatively.
