To take good care of your teeth and keep toothache at bay, first of all you need to avoid sugary foods. Not only are these especially bad for your teeth, but they are also not particularly healthy anyway.
Next, you need to brush your teeth regularly, to get rid of any food debris remaining on your teeth after meals. It is a good idea to brush your teeth after each meal, and especially before going to bed at night. Brushing the teeth breaks down the plaque, and so helps to prevent tooth decay which then leads to toothache.
Before brushing, there are two things that you should do to make sure that your mouth and teeth cleansing are effective. You should first of all floss your teeth with dental floss or dental tape, to really clean in between your teeth. It is in between the teeth that bits of food can get lodged, and your brush cannot effectively reach them there. Next, you should rinse your mouth out with a good mouthwash, as this serves to loosen the plaque that gets stuck to teeth and attracts the bacteria which eventually lead to tooth decay.
You may give some thought to the type of brush that you use as well. Most toothbrushes nowadays are made from nylon, but a brush that is kinder to your teeth is the one made from pig bristle. This gives your teeth a really good cleaning without damaging or being too harsh to the enamel. You should really change your toothbrush every three months, as it loses its effectiveness over time.
Some toothpastes contain fluoride and some don't. Fluoride helps to make the enamel of your teeth stronger and more resistant to the cavities that cause toothache.
Develop a good brushing technique. Brush away from the gums, and be sure to brush firmly, paying attention to both the front teeth, (the incisors), the back teeth, (the molars), and the ones in between, (the pre-molars). Brush both the outer side of the tooth, and the inner side. To get the awkward bits in between the teeth you should use an inter-dental brush. The inter-dental brush is also good for getting the very back of your teeth, the wisdom teeth, where it is sometimes difficult for a conventionally sized and shaped brush to reach. After brushing your teeth, rinse your mouth out well with water.
Another important way to look after your teeth is to have regular dental check-ups. Don't wait until you get a toothache before you visit a dentist, because by then it will be too late. You can prevent the causes of toothache by having a check-up every six months, so that the dentist can catch any problems early on.
Take care of your teeth, and they will last you a lifetime.