Hi Deepak
There are lots of teeth whitening products out there and a lot of them are on the internet.
There are toothpastes (helps, but does not make a dramatic difference), home bleaching products such as whitening strips, mouth trays using a bleaching system you use at home which you can find on the internet or obtain from your dentist, and laser bleaching which done by a dentist only.
Many of them are cheaper than what your own dentist may offer you, however... not all products have been tested and approved by the ADA (American Dental Association) for effectiveness and safety.
You may wish to visit the ADA web site for consumers for more information regarding teeth whitening products before you make a decision. Here is a link:
http://www.ada.org/public/topics/whitening_faq.asp
Below is a list of the currently approved products (over the counter and dental office products):
Colgate-Palmolive Co.
Dentifrice, Fluoride, Whitening, Tartar Control
Colgate Tartar Control Plus Whitening Gel
Dentifrice, Fluoride, Anti-Plaque/Anti-Gingivitis, Whitening, Tartar Control, Oral Malodor
Colgate Total Advanced Whitening Toothpaste
Dentifrice, Fluoride, Anti-Plaque/Anti-Gingivitis, Whitening, Tartar Control
Colgate Total Plus Whitening Gel
Colgate Total Plus Whitening Toothpaste
Colgate Total Whitening Liquid Gel Toothpaste
Procter & Gamble Co.
Dentifrice, Fluoride, Whitening, Tartar Control
Crest Extra Whitening with Tartar Protection Toothpaste, Clean Mint (Neat Squeeze Version)
Crest Multicare Whitening Toothpaste, Fresh Mint (Neat Squeeze Version)
Dentifrice, Fluoride, Anti-Plaque/Anti-Gingivitis, Whitening, Tartar Control, Desensitizing
Crest Pro-Health Whitening Toothpaste
Dentifrice, Fluoride, Desensitizing
Crest Sensitivity Protection Soothing Whitening Mint Paste
Ultradent Products, Inc.
Whiteners/Bleaches, Dentist Dispensed/Home-Use
Opalescence Whitening Gel 10%