TEETH whitening, though seemingly rather new in the field of dentistry, has actually been around since the 17th Century, when people would visit their barbers for a haircut and teeth whitening.

Back then, barbers would extract teeth after securing the patient’s (or victim’s) head, arms and legs with leather straps. Or, you could simply choose to whiten your teeth. The barbers filed down the teeth and applied an acid to them that would cause them to whiten. Of course, this was a fairly painful procedure, harmful to teeth, and a far cry from where we are today.
Then, in 1884, hydrogen peroxide was introduced for teeth bleaching, and the use of high-intensity lights were added to accelerate the whitening process, starting around 1918. In those days, there were very few cosmetic dentists, and teeth whitening was a procedure that was hardly known.
It was not until the 1980s that in-office teeth whitening started to become popular, and the early 1990s when over-the-counter whitening products became available, thanks to the use of carbamide peroxide. As a result, the dental landscape has since been changed, opening up the doors to hundreds of whitening products and helping to usher in the age of the smile makeover.
Teeth whitening is a way to reverse the signs of age in teeth, and remove the years of cumulative stain from coffee, tobacco, lipstick and the numerous colourful foods and/or drinks. These unsightly stains can be removed by utilising in-office whitening systems custom home trays, and some over-the-counter products.
For the latter, I would only recommend Zoom! and Britesmile. These work for one hour, and can bring the teeth up to 14 shades lighter. But your dentist needs to advise you and monitor its use, assuming that it would be appropriate in your case.
Over-the-counter whitening products such as whitening toothpastes, strips, rinses, flosses and whitening chewing gum are relatively ineffective at best, and some of the whitening pastes can be very abrasive, and actually cause damage to the enamel.
The main reason for their relative futility is because the Food and Drug Administration (F.D.A) of the USA cannot permit pharmaceutical manufacturers to exceed a certain limit of the active ingredients of these products when the public can have free access to them.
My personal view is the reason why they are so popular and very marketable is because of advertisement, psychology and low cost. Brushing with whitening toothpaste removes the extrinsic (surface) stains by mechanical means; little to no change in colour actually takes place. The “whitening” is deceiving on these products, because, if it rubs off a little extrinsic stain, that does not mean the teeth have been whitened. You need a bleaching agent such as carbamide peroxide or hydrogen peroxide in order to intrinsically whiten teeth. And they must be in the right concentrations. Additionally, these chemicals must remain in contact with the enamel for a certain period of time in order to be effective. Even toothpastes that claim to have these agents are not very effective, because they have a mild concentration of peroxide, and are not in contact for a long enough duration to make any difference.
The American Dental Association (ADA), of which I am a member, has lent its support and approval for enhancing the aesthetics of one’s smile via in-office and home bleaching, and has given its Seal of Approval to a number of whitening systems.
The safety and effectiveness of this procedure is directly related to the dosage given, the frequency and duration of treatment, the concentration and type of material used, and the type of tray and system utilised.
Like anything else, it can be abused, and cause adverse results. During the time you whiten, the fluoride-rich layer of the enamel is broken down, and the teeth become porous, making them more susceptible to the acids and sugars in your mouth. Within 24-48 hours, your tooth’s enamel will re-mineralise and build up that protective fluoride-rich layer again. So, whitening too often will cause long-term adverse effects on your teeth.
Those persons with restorations of any type on their front teeth, within or covering their tooth structure, such as fillings, bonding, crowns, veneers, etc. should not do whitening, because they must realise that those areas will not whiten. If they still choose to go ahead, they should do so with the understanding that they may require new restorations in order to match the newly whitened shade.
Finally, it is imperative that one’s dentist performs a proper examination and diagnosis, in order to identify abscessed teeth, existing cavities, internal or external resorption, and other diseased conditions in the mouth before bleaching. A cleaning must also be done prior to any whitening procedure.