What you should know is that you shouldn't panic if you observe that your teeth have stains. All you have to do is to go to your regularly dentist for an oral exam. He is the best qualified to recommend you a good cosmetic dentistry procedure for teeth whitening. There are many different ways to recover your beautiful smile.
The most common method for teeth whitening is using a good recommended and tested whitening toothpaste. This is also a good teeth maintenance method. Another teeth whitening product that you can use is a whitening gel or whitening strips. Combined with a good whitening toothpaste will bring you great results.
Best way to deal with yellow teeth is by bleaching. Teeth can get yellow stained, striped or molted from tobacco, coffee and food. Molted teeth or to much fluoride may not respond even to the bleaching treatment. This is quite a big teeth whitening problem and the best way to resolve it is to ask your dentist for advice.
The periodontal disease is a nasty gum illness that many people have. I would suggest you not to use any chemical teeth whitening techniques that could irritate your gums pretty bad. Also if you have tooth fillings that are colored, crowns or bonding in your front teeth I would not recommend you bleaching because you won't see any results.
You can always try some traditional mouth to mouth transmitted methods but the best teeth whitening techniques are the ones recommended by your personal dentist.