As with many things in life, the teeth that you have now need to last you a lifetime, so you need to care for them well in order to have a healthy smile. Once problems start, you may begin to suffer from problems, such as gum disease, cavities and abscesses.
Buy a high quality toothbrush and make sure that you replace it. It has to be soft enough not to hurt your gums. Try to replace your toothbrush once a month to avoid bacteria from building up on it.