Dental caries or tooth decay is a disease.It involves a process where the enamel of the teeth loses minerals( a process called demineralisation) due to an acidic environment in the mouth causing the surface to become more permeable to bacteria. (Our mouth is loaded with them,if you are not aware!) .Once bacteria gains entry into the tooth structure,they continue to proliferate by metabolizing the sugar (glucose,sucrose,fructose,lactose etc) in our diet.The by-product of this process is more acid that continues to destroy more tooth structure.
To treat tooth deacy,you basically need to have fillings done.

However,we are now looking at diagnosing a pre-decay condition and taking steps of prevention.
Before that,just a bit of chemistry of the disease:-
Acid dissolves tooth structure.The source of acid can be extrinsic (bacterial and deitary/environmental) or intrinsic(stomach acid reflux) or a combination of both.
A process called demineralisation occurs.What is seen on the tooth surface is white patches called white spot lesions,which when left unattended ,will deteriorate to a cavity.
Now we are looking at how to neutralise the oral environment and remineralise the tooth surface.
As long as the tooth surface is still intact ,bacterial molecules are too big to penetrate enamel layer,therefore there is the opportunity to remineralise.
Firstly,we have to stop the demineralisation by raising the pH in the oral cavity.

Normal salivary flow is usually sufficient as a buffer to neutralise the normal acid levels in the oral cavity.In situations where salivary flow is reduced due to certain reasons(consumption of certain medication/post radiotherapy/certain systemic diseases),some form of ph-raising oral rinse is required.There are also some products that stimulate salivary flow.
Personal habits like use of nicotine,alcohol,caffiene etc can also cause lower salivary output .These substances act as a diuretic .Our body’s natural reaction is to conserve fluid,therefore it will produce less saliva in the presence of high levels of these substances.

We start by eliminating sources of acid in our mouth.
Dietary habits need to be noted and changes made where necessary ,for example,we should halt consumption of food and drink that have high sugar content and with low pH/how acidity.
If there is a problem with instrinsic acid where gastric reflux is a problem,then one should seek the advise of a physician.
For bacterial acid,there are antibacterial treatment options that your dentist can recommend.

Of absolute importance is of course ,good tooth brushing with a fluoride-containing toothpaste and proper flossing .
In conclusion,we should aim to modify the chemistry of the oral cavity to one of non-acidic nature.