You could go to a dentist and have them whitened, but that's expensive, and as with most hydrogen peroxide based whiteners (even over-the-counter) there is the potential for tooth and gum sensitivity. In fact, they say up to 2/3 of patients will encounter some form of sensitivity. I'll pass, thank you. My teeth are too precious to experiment with that.
You'll be happy to know that there are some natural alternatives, some of which are rather surprising.
1. Strawberries: Yes, believe it or not, these red berries can actually whiten your teeth. Mash and rub or brush on teeth. BUT, remember because of the acid and sugar in the berries, you should immediately floss and then brush with your regular toothpaste. Actually, brushing after eating will help prevent staining.
2. Baking Soda: Although it won't bleach the teeth, it will remove stains and make them shine. You can either add to your toothpaste or wet your toothbrush and pour some on, brush and then rinse. This should only be used twice a month as Baking Soda is abrasive and can remove the enamel from the teeth.
3. Baking Soda and Peroxide: Apparently, this is the best combination.
1. Pass on the coffee, red wine, dark syrupy sodas and blueberries. Or if you do partake, immediately rinse with water.
2. Give up smoking, your lungs, teeth and your friends will thank you.
3. Use a straw when drinking stainworthy liquids.
4. Eat more raw, crunchy veggies. They can remove surface stains.
5. Chew sugarless gum, it stimulates the salivary glands which cleans the surface of your teeth. There are several sugarless gum brands you can buy in the health food store that don't have preservatives, artificial sweeteners and other icky chemicals. ECODENT, Xylitol and Peelu.DO NOT USE LEMON JUICE. Although, it is often recommended, lemon juice is not a good alternative. Yes it will brighten your teeth, but the citric acid will also strip the calcium from your tooth enamel, leaving you much more susceptible to tooth decay. You'll have lovely white teeth and tons of decay. Not worth the trade off, in my opinion.
For more interesting dentifrices check out Dr. Paul H. Keyes. He has some interesting natural solutions for good dental health.