How does sugar damage your teeth?

If not brushed off pretty soon, it coats your mouth with a nice yummy breeding ground for bacteria that cause cavities and gum infections.
Sugar proceeds into your stomach, where it turns into glucose, which you need, just not as much as we eat in sugar (it's in starchy foods too).
Too much, and we don't have enough defenses anymore, and we get inflammation.
I spent my 69 years eating far too much sugar, and I am in a lot of pain. (Not all from that, but partly.)

If this is a homework question, my answer won't be good enough. Google 'dental caries.'

Sugar feeds acid producing bacteria in your mouth. The acid literally decays your teeth like rot in wood.

Tooth decay is caused by bacteria in the mouth using sugar from food and drinks to produce acids that dissolve and the teeth.

Tooth decay is caused by bacteria in the mouth using sugar from food and drinks to produce acids that dissolve and the teeth.

After eating sugar contents entered inside area parts of teeth basically the inside big ones,and it not goes out,if not proper brushing the bacteria particles entered there and it grows more on that particular teeth side and reproduces the tooth pain

It is responsible for tooth decay. Hundreds of bacteria reside in our mouth. Many are good for our oral hygiene while others are harmful. They are the food food for those bad bacteria and when these bacteria grow in your mouth, teeth, gum and other areas get in trouble. Enamel (the upper layers of your teeth which contains mineral) will be lost. This situation is also known as tooth enamel loss or decay. Cavities will be produced in between your teeth and if not cured then cavities grow and give rise to many other problem. Hope it helps. Google can give you deeper answer.