In response to the statement: “Lime juice and salt for teeth harmful.”
Yes! Never use salt to brush the teeth!
Salt is a mineral. It is abrasive. It does not completely react with weak solutions. It dissolves in them. Salt is a preservative and it will weaken the enamel of the teeth and make the teeth brittle. Using salt to brush the teeth will cause the teeth to become very weak and the teeth will chip off in a very short time.
There was a Chinese “doctor” who even suggested using salt to brush the teeth! He is either someone who has never used salt on his teeth, or he is someone who is toothless!
Dentists who use electric polishers to clean the blackened teeth of a longtime smoker usually directly “attack” the teeth without first trying to remove the black stuff with oxygen. Abrasion is much less effective than oxygen in cleaning teeth.
The basic teeth whitening effect is the result of a chemical reaction between an acid and a base that produces pure oxygen. It is the oxygen that cleans the teeth, not the base. The chemical reaction is a complete conversion to oxygen and the acid and the base involved are not harmful to the teeth.
The harmless acid and base combinations that are generally used to whiten teeth are: hydrogen peroxide as a gargle or rinse as indicated on the label; hydrogen peroxide and baking soda; lime juice and baking soda; white distilled vinegar and baking soda which I use instead of toothpaste; occasional vinegar condiment such as Japanese vinegar and baking soda if you run out of distilled vinegar.
Apple cider vinegar is sweetened and is too weak an acid. Fresh squeezed lime juice is a very strong acid.
A mouth full of vinegar a day keeps the teeth clean and cavities away.