There is no toothpaste or drop by which you can prevent cavity. If the cavity is already formed then you have to go to the dentist to get the filling done or else the cavity will increase and ultimately lead to either rct and capping or in more worsen condition the tooth need to be removed. Tooth paste has no key role in preventing cavity, its your way of brushing and your dietary habits and how many times you are brushing plays important role in preventing caries.

Here is no remedy for that except for that u need to visit the dentist to get it cleaned professionally and restored back to good health ... before u end up in severe pain once the nerves are involved and u end up in getting an root canal therapy ....

first of all there is no such toothpaste that can prevent cavities. what matters is how you brush your teeth and keep your oral hygiene. and if you have cavity visit dentist for restorartion/filling

Pls visit dentist and get proper treatment done. No medicine can help u in healing the same. The more u delay the more problems and the cost for treatment would increase proportionately