When it comes to tooth whitening
, the best place to start is with your dentist
. In general it is recommended that you visit a dentist for a cleaning and exam twice a year. You can then make sure that your teeth are healthy and talk with your dentist about any cosmetic procedures that you may be considering.
There are many options available for whitening your teeth and your dentist can give you an overview of the various options and what might work best for the effect you are looking for as well as your budget. You are correct that the OTC strips and the mouthwash using the same chemical formulations are much, much cheaper than any of the options offered by dentists. For many people, the whitening strips can work well and give them the added whitening they were looking for.
However, the options the dentists can provide are more effective: the question is will they be so much more effective for you that you are willing to pay the additional cost? Dentistry options range from prescription trays with evening whitening gel that you wear overnight to porcelain veneers
that are quite expensive but are essentially lifetime "perfect" teeth. The most important thing is to talk to your dentist and make sure that your teeth are healthy, and then you can decide what cosmetic options fit your budget both for now and later.