Dental caries (tooth decay) is a major oral health problem in most industrialised countries
affecting 60–90% of schoolchildren and the vast majority of adults.
The early manifestation of the caries process is a small patch of demineralised (softened) enamel
at the tooth surface, often hidden from sight in the fissures (grooves) of teeth or in between the
teeth. The destruction spreads into the softer, sensitive part of the tooth beneath the enamel
(dentine). The weakened enamel then collapses to form a cavity and the tooth is progressively
destroyed. Caries can also attack the roots of teeth should they become exposed by gum
recession. This is more common in older adults.
Dental caries is caused by the action of acids on the enamel surface. The acid is produced when
sugars (mainly sucrose) in foods or drinks react with bacteria present in the dental biofilm
plaque on the tooth surface. The acid produced leads to a loss of calcium and phosphate from
the enamel; this process is called demineralisation.
Diagnosis of dental caries
A device for rapid diagnosis of dental caries in saliva of a patient by means of a reagent which
changes color in the presence of dental caries or dental caries-causing microorganisms
comprising a piece of ground paper, a supporting film peelably adhered by an adhesive layer
backing to the ground paper in a first region, a coating film having an inner surface and an
adhesive layer at least around the periphery of the inner surface of said coating film, a piece of
filter paper which has been impregnated with a solution containing a reagent which changes
color in the presence of dental caries or dental caries-causing microorganisms and then dried,
said piece of filter paper being supported on said inner surface of said coating film, said coating
film being peelably adhered by its adhesive layer to the ground paper in a second region in such
a manner that said piece of filter paper is completely kept from open air or air circulation and is
maintained in a germ-free condition.
Years ago; the focus has been on the link between water and fluorides and dental caries
and fluorosis, topical fluoride applications, fluoride toothpastes, and salt and milk
fluoridation.Most recently, efforts have been made to summarize the extensive database through
systematic reviews. Such reviews concluded that water fluoridation and use of fluoride
toothpastes and mouthrinses significantly reduce the prevalence of dental caries. WHO
recommends for public health that every effort must be made to develop affordable fluoridated
toothpastes for use in developing countries. Water fluoridation, where technically feasible and
culturally acceptable, has substantial advantages in public health.