Given below are some useful tips to keep your teeth healthy for as long as you want:

Drink plenty of water.

Eat a variety of healthy foods from all the five major food groups.

Avoid high-sugar foods.

Brush twice a day.  

Learn the correct way to brush & Remember to floss everyday from the dentist. 

Avoid aggressive brushing.

Get your teeth checked and cleaned every six months.

Rinse your mouth thoroughly after every meal.Get all existing dental problems—bleeding gums, missing teeth, cavities—treated immediately. Prolonging treatment can lead to further severe complications. Bad breath may be caused by existing oral diseases such as gum disease and Candida infection. In such a case, see your dentist as soon as possible.

Have herbs, the natural antibiotics. Fresh parsley and aloe vera are effective in preventing bad breath. Chew fresh parsley whenever you can. It not only detoxifies your mouth, but it also contains abundant chlorophyll, which sweetens your breath. Furthermore, all this will increase the flow of saliva that helps avoid dry mouth. 

Eat crisp fruits and vegetables such as apple, cucumber and carrot. Chewing them cleans the mouth naturally by removing plaque and food particles stuck between your teeth and gums.

Chewing sugarless gum increases salivation. Saliva has anti-bacterial properties so the more saliva you have, the more you suppress the bacterial growth. Fennel seeds, cinnamon sticks, mastic gum and fresh parsley are some of the commonly found food items that help you salivate naturally.

Stay away from foods that cause foul breath such as raw garlic, onions, meats, fish, and cheese.