First, let me say congratulations not only on having few dental needs but also on your obvious commitment to preventive dentistry. There are a number of ways in which a dentist can whiten teeth. They are as follows: 1) bonding, 2) bleaching (also known as whitening), 3) porcelain veneers 4) crowns or caps and 5) a combination of any of the above.
Because you have noted that you have had very few dental needs throughout life, it is most likely that you are a good candidate for bleaching (whitening). There are two methods to whiten teeth that are available. The first method is a procedure that is done in the dental office through the application of whitening solutions directly on the teeth. Depending on the degree of staining you can get beautiful results from as little as one visit. The other method used is an at-home whitening system. The procedure for this system is as follows. You would have impressions made of your teeth whereby the dentist could make a duplicate model of your teeth. Utilizing this model, your dentist would fabricate a gel tray that intimately fits your teeth to the point that you might not even know it is on. Your dentist would dispense a whitening solution to be placed in this tray and then on your teeth. Typically, a patient would do both upper and lower teeth at once for one hour a day. You can expect beautiful results in 5 to 14 days depending on the system your dentist is using and the condition of your teeth.
One thing to be aware of when whitening your teeth is that if you have white fillings in your front teeth that are noticeable upon smiling, they will not whiten with this procedure. What is normally done is they will be replaced once the desired result is attained. If you have crowns or caps the same holds true, except that to replace a crown is more costly than replacing a filling.
It is important to realize that a thorough examination by your dentist is imperative. There may be things going on that need to be addressed prior to initiating whitening. Because of this, I would discourage anyone from using any over-the-counter product without consulting their dentist first. The results attained through proper whitening or a combination of the above techniques are very predictable and can greatly improve one's self-image