I'm new to this thread, juz so happened to come across this thread and happened to know a bit here and there n would like to share...
There are basically 2 types of stains : intrinsic/internal(eg certain antibiotic causing ones) and extrinsic/external(eg food, coffee, smoking stains). Contrary to many advertisements, it is difficult to obtain flawless white teeth. Healthy human teeth have extremely subtle yellow, brown or gray tones. Pure white teeth are like purple hair -- they appear synthetic and distracting! Light natural tooth shades compliment everyone's facial features.
Here are eleven simple, low-cost tips to enhance your smile:
1. Use a straw to drink cola, tea, coffee, grape juice, red wine and other beverages that stain teeth. This method limits the amount of beverage that contacts the teeth.
2. Reduce drinking extremely hot or cold beverages. Hot coffee and ice tea are especially hazardous to your smile because they change the temperature of your teeth. This temperature cycling causes teeth to expand and contract allowing stains to penetrate the tooth enamel.
3. Avoid white clothing. Wear off-white or dark apparel instead. A plain white shirt or blouse makes even the whitest bleached smile appear yellow. That's why a darker-complexion person seems to have white beautiful smile.
4. Wear a bright shade of purple or pink-based lipstick. Your teeth will appear lighter. Avoid orange or brown lipstick shades.
5. Darken your hair color. Bright teeth contrast well against dark hair and skin. (Skin tanning is not advised due to the risk of developing premature wrinkles or skin cancer.)
6. Do not smoke or chew tobacco. Tobacco quickly stains teeth yellow and brown. It also causes the gums to pull away from teeth and expose tooth roots. The sugar used to flavor smokeless tobacco causes tooth decay. Tobacco also causes oral cancer.
7. Limit consumption of acidic foods. These foods open up the pores of the enamel, allowing stains to easily penetrate the tooth.
8. Brush your teeth or rinse them with water immediately after eating a snack or drinking a beverage. Avoid abrasive whitening toothpastes, since there is only limited evidence that tartar control, baking soda or peroxide toothpastes remove stains more effectively than regular fluoride toothpaste.
9. If possible, avoid tetracycline ( a kind of antibiotic) drugs while teeth are developing. They can stain teeth yellow. And excessive amounts of fluoride can cause unsightly brown pits in the enamel.
10. Have your teeth professionally cleaned and polished every six months.
11. If you require dental work, discuss esthetic options with your dentist. Amalgam fillings, gold crowns and other dental restorations can also stain teeth. A composite (tooth colored) filling may be a viable alternative to an amalgam (silver) filling in certain situations.
"A smile creates happiness in the home, fosters good will in business and is the countersign of friendship. It brings rest to the weary, cheer to the discouraged, sunshine to the sad and is nature's best antidote for trouble. Yet it cannot be bought, begged, borrowed, or stolen, for it is something that is of no value to anyone until it is given away. Some people are too tired to give you a smile. Give them one of yours, as none needs a smile so much as he who has no more to give."