Diet
Your mouth, like the rest of your body, needs good food to sustain it. Sugary foods and some fizzy drinks are damaging to the teeth. The sugars react with the bacteria on your teeth, producing harmful acids that attack the teeth. Regular brushing can help prevent damage to your teeth from these foods, and if you have eaten something sugary it can help to give your teeth an extra brushing about an hour after eating. If you can reduce your intake of these foods, that is even better. It is not so much the quantity of sugary foods that affects the teeth, but the frequency with which you eat them: in other words, have them less often.
Fizzy drinks, even when sugar free, can contain high levels of acid. Other acidic foods, such as pickles, can also harm your teeth. The acid attacks the enamel coating of your teeth leading to decay. Again, having these foods less often will significantly improve the condition of your teeth.
Your general oral health, (for example, the health of your gums, bones and tongue), can be supported by having a good, balanced diet. A diet including plenty of fresh fruit and vegetables, fibre, minerals and vitamins, will help you develop healthy gums (and will be good for the rest of you too!)