Welcome to HCM forum. Sorry Mr Rajesh, there is no other way to prevent dental decay once it started forming. It is better for you to contact a dentist as soon as possible and get your decayed teeth filled. Otherwise It will go on increasing and will soon destroy your tooth. Drilling and filling in no way causes more cavity formation. Maintain your oral hygiene. Brush your teeth twice a day with fluoridated tooth paste, avoid sticky sugars, and visit your dentist for review every 6 months.

Unfortunately, decay is irreversible. It can not, and will not, heal on it's own.

The cells that made your teeth (ameloblasts and odontoblasts) died after they formed your tooth. They are no longer around to "do repairs" when your teeth are damaged. This is the opposite of other tissues, like bone, which retain the cells that formed them and can repair itself. The teeth in your mouth are subject to the simple chemistry of demineralization and demineralization. This can be done on a small scale, but not to fix decay.

The closest thing to an "all natural" treatment is fluoride. Fluoride occurs naturally in the water (although some places add additional) and has been shown to significantly lower rates of decay.

Please keep in mind the that "drilling" a dentist does in merely removing decay, which is your stated goal. A filling, literally just fills in the space that decay left. Just like everything in life, a filing will only last so long. The problem is not the filling itself, but new decay.

Best of luck. I hope you seek dental care from a professional.