Is there anything i can do to keep my teeth my teeth perly white...they are turning yellow day by day.?

NO, pearly white isn't possible but you can expect some improvement you can do:-

1. Thoroughly brush and floss your teeth. This will help remove any build-up that will prevent your teeth from being whitened. Flossing your teeth will remove plaque in between your teeth and will ensure that this area is whitened as well.

2. Use hydrogen peroxide. Commercial whitening kits aren't cheap; for a cheaper solution, you might like to consider whitening your teeth at home using hydrogen peroxide for a similar effect. Bleaching teeth with hydrogen peroxide is acknowledged as a safe practice by the American Dental Association.

Pearly White?

1 Avoid the consumption of or exposure to products that stain your teeth, such as coffee, tea, and red wine.

2 Brush or rinse immediately after consuming stain-causing beverages or foods.

3 Follow good oral hygiene practices. Brush your teeth at least twice daily and floss at least once daily to remove plaque. Use a whitening toothpaste (once or twice a week only) to remove surface stains and prevent yellowing. Use a regular toothpaste the rest of the time.

4 Consider touch-up treatments. Depending on the whitening method used, you may need a touch-up every 6 months or after a year or two. If you smoke or drink lots of stain-causing beverages, you may need a touch up more often.

Foods high in cellulose such as carrots, apples, cellery etc. cleanse and remove surface stains naturally. Also switch to a tooth paste with baking soda or just brush with baking soda once a week. You can take baking soda and a lemon, in a small bowl sweeze the lemon juice onto baking soda, mix should slightly bubble, then take a cotton swab wipe off saliva and plaque from teeth then rub the mix onto your teeth, leave on your teeth for one minute no longer or acid from lemon will erode tooth enamel.I bought the Luster system because I've tried whitening gels and my teeth are very sensitive but this is very easy to use and causes no sensitivity what so ever. You just brush the solution onto your teeth and it comes with a uv light you just hold up to your mouth. Its very easy to use, inexpensive, and it actually works!!! Also if you want a simple, very cheap way to whiten and just give them back their natural color you can swish peroxide around in your mouth as long as you can. Good Luck

crest whitening strips i heard were good