Teeth whitening techniques can be divided into two basic categories, at home and in office whitening. Otherwise known as professional teeth whitening. We will go into the pros and cons of each, but it is important to realize that this article only refers to the techniques for whitening tooth structure through chemical means to get a more esthetic color for the actual tooth enamel. This does not include "veneers" or "composites" which are restorations which can change the color and shapes of teeth by adding material to them. In fact, it is not possible to change the color of restorative material so if a patient has restored front teeth they will not change color with any tooth whitening technique professional or otherwise.
All "teeth whitening" is currently done by the chemical carbamide peroxide. It is the active ingredient in all tooth whitening systems including over the counter, at home, and in office techniques, professional teeth whitening. The difference between each system which dramatically effects its success is the means of applying carbamide peroxide to the teeth and the concentration of the chemical used. If you think about it, for a chemical to lighten the very hard enamel of a tooth it has to be fairly caustic. It needs to permeate the enamel to lighten it. It also follows, that the more concentrated the tooth whitening gel, the more harmful it could be to the soft tissues of the mouth like the gums and lips. As a rule, over the counter tooth whitening like "strips" or "whitening toothpaste" have very low concentrations of carbamide peroxide. I have seen products that range from 1-8% carbamide peroxide in over the counter systems. This is very low and it makes sense because users are just placing it themselves without protecting the gums and lips. If it was highly concentrated it would burn the soft tissues causing pain, swelling, and sores. From my experience, these systems are ineffective and appear to be low cost but require repeated use to get only minor results.
Professional teeth whitening trays are made from impressions of the teeth and are designed to hold whitening gel against the teeth while keeping it off of the gums. This allow the patient to use more concentrated whitening gels that range form 12-24%. These higher concentrations naturally do a much better job of teeth whitening and the time of use can be controlled by the patient. The longer time the peroxide based gel is in place, the better the results.
The third means of applying gel is an in office, one visit Professional teeth whitening. These are of course the most expensive but they also give the most dramatic results. These system use the highest concentration of whitening agent and very intense light to help it permeate the enamel of tooth structure. In these cases, it is very important that the gums, lips, and skin around the mouth be completely protected from the gel and the light. Unprotected, any of these soft tissues would be burned. These systems like "ZOOM Teeth Whitening" are very effective and patients get dramatic "whitening" of teeth. The appointments take up to 2 hours because of the need to protect all the tissue and allowing time for the chemicals to work. I prefer to combine this with professional teeth whitening trays because it allows patients to touch up their bleaching for years after and also is a means of applying other chemical agents which help with sensitivity issues.
There are lots of studies that show whitening does not damage the integrity of teeth whether it is professional ZOOM Teeth Whitening or over the counter teeth whitening. It is important to note that some patients develop sensitivity. This is particularly true in patients that have gum recession or sensitive teeth in the first place. Most often, treating the teeth with fluoride gel alleviates this issue. Often, I instruct patients to use fluoride gel before whitening to help minimize sensitivity. It is also very important to realize that after any whitening, the teeth are porous. The greater the change in color the more the carbamide peroxide has permeated the teeth. This porosity goes away, but in the short term you have to be careful. If you whiten teeth and leave the office and meet your friends for a glass of red wine, it will alo permeate the teeth and have the opposite effect. If you use teeth whitening strips and go out for coffee you have made a mistake. Just remember to stay away from intensely colored food for a few days after whitening, any whitening. In my system we utilize clear fluoride gel to desensitize and seal up teeth after whitening but we still give diet instruction for 2-3 days.