The Whitening Phenomenon: Fact vs Fiction
Whitening has become a virtual phenomenon evidenced by the vast array from over the counter products, mobile and ‘spa’ whitening to the more sophisticated professional whitening programs all driven by consumer demands.
According to a recent survey, 85 per cent of the general population surveyed said they would like to improve their smile by making their teeth whiter, noting one of the first things people notice is your smile. In fact, according to a 2004 survey conducted by the American Academy of Cosmetic Dentistry (AACD), almost all adults consider an attractive smile to be an important social asset that makes a person more appealing to the opposite sex.
The obsession with the attainment of a whiter and brighter smile began quite innocently. The use of hydrogen peroxide dates back more than 100 years; its original purpose was to aid wound healing by reducing the anaerobic microbial population. The unintentional outcome’along with enhanced healing’was a distinct ‘whitening’ of the tooth enamel.
MECHANISM OF ACTION
Whitening of the tooth structure involves the use of namely hydrogen peroxide and/or carbamide peroxide which remove color from the tooth matrix by oxidation. Hydrogen peroxide on its own is very unstable and remains active for only 30 to 60 minutes with most of its activity occurring in the first 30 minutes after application. Carbamide peroxide, in contrast, releases about 90 per cent of its active ingredient in the first two hours with the remainder released over the next four to six hours contingent on factors such as pH variance and salivary flow. This delayed release brought about the introduction of the overnight whitening product.
As dental professionals we are often called upon to recommend an effective whitening system to meet the needs of today’s dental client. There are a number of facts as well as some common misconceptions to consider.
Fact: We know that the principle of oxidation works to remove stain from the tooth matrix.
All products containing a percentage of hydrogen peroxide or carbamide peroxide report some degree of efficacy.
Myth: Professional tray whitening time is 21 days.
Fact: Achieving optimal results with tray whitening is dependent on the cause and nature of the discoloration of the tooth structure. This is why it is imperative to perform a comprehensive assessment first. Whitening results may be achieved within a few days or take several months as in the case of tetracycline staining. All tooth structure will have a saturation point whereby no further whitening can be accomplished.
Fact: Professionally administered whitening in a controlled environment has been proven to be safe. Professional tray whitening has the longest history of safety in controlled research. The majority of the studies have been done with 10 per cent carbamide peroxide.
Myth: Hydrogen peroxide delivers the highest degree of whitening.
Fact: Carbamide peroxide offers the most stable, long lasting result with whitening. Using carbamide peroxide at a low percentage provides the least chance for sensitivity. Generally the higher the hydrogen peroxide concentration, the greater the chance transient tooth or gingival sensitivity.
Myth: Fluoride provides the highest degree of control over hypersensitivity incurred through the whitening process.
The combined regimen of proactively addressing potential areas of hypersensitivity prior to the commencement of whitening with a five per cent sodium fluoride varnish followed by daily use of a calcium phosphate toothpaste such as NovaMin preceding, during, and for several days afterwards will serve to deliver a sustained degree of desensitization. NovaMin is an inorganic compound that is engineered to elevate the oral pH resulting in a rapid and continuous release and deposition of a natural crystalline hydroxyl-carbonate apatite layer that is chemically and structurally the same as tooth mineral, thus reducing hypersensitivity.
In conclusion, professional tray whitening systems combining the fast action of hydrogen peroxide and the long lasting stable result of carbamide peroxide are among the most efficacious whitening products available to the consumer today.