Whitening methods can de divided into two types, including in-office bleaching (applied by a dental professional), and home whitening treatments.
Bleaching solutions generally contain hydrogen peroxide or carbamide peroxide, which bleaches the tooth enamel to change its color. Off-the-shelf products typically rely on a carbamide peroxide solution varying in concentration from 10% to 44%. Bleaching solutions may be applied directly to the teeth, embedded in a plastic strip that is placed on the teeth or uses a gel held in place by a mouthguard. Carbamide peroxide reacts with water to form hydrogen peroxide. Carbamide peroxide has about a third of the strength of hydrogen peroxide. The peroxide oxidizing agent penetrates the porosities in the rod-like crystal structure of enamel and breaks down stain deposits in the dentin.
Before the treatment, the dentist may examine the patient: taking a health and dental history (including allergies and sensitivities), observe hard and soft tissues, placement and conditions of restorations, and sometimes x-rays to determine the nature and depth of possible irregularities.
The whitening shade guides are used to measure tooth color. These shades determine the effectiveness of the whitening procedure, which may vary from two to seven shades. The effects of bleaching can last for several months, but may vary depending on the lifestyle of the patient.
In-office bleaching procedures generally use a light-cured protective layer that is carefully painted on the gums and papilla (the tips of the gums between the teeth) to reduce the risk of chemical burns to the soft tissues. The bleaching agent is either carbamide peroxide, which breaks down in the mouth to form hydrogen peroxide, or hydrogen peroxide itself. The bleaching gel typically contains between 10% and 44% carbamide peroxide, which is roughly equivalent to a 3% to 16% hydrogen peroxide concentration.
Bleaching is least effective when the original tooth color is grayish and may require custom bleaching trays. Bleaching is most effective with yellow discolored teeth. If heavy staining or tetracycline damage is present on a patient’s teeth, and whitening is ineffective (tetracycline staining may require prolonged bleaching, as it takes longer for the bleach to reach the dentin layer), there are other methods of masking the stain. Bonding, which also masks tooth stains, is when a thin coating of composite material is applied to the front of a person’s teeth and then cured with a blue light. A veneer can also mask tooth discoloration.
Power or light-accelerated bleaching, sometimes colloquially referred to as laser bleaching (a common misconception since lasers are an older technology that was used before current technologies were developed), uses light energy which is intended to accelerate the process of bleaching in a dental office. Different types of energy can be used in this procedure, with the most common being halogen, LED, or plasma arc. Use of light during bleaching increases the risk of tooth sensitivity and may not be any more effective than bleaching without light when high concentrations of hydrogen peroxide are used. In The Smile Bar, within just 20 minutes, we can make your teeth between 2 to 9 shades whiter using a very effective teeth whitening gel with a revolutionary formula, and a sophisticated whitening lamp for immediate visible effects. Click here to see the whitening results in The Smile Bar.
The ideal source of energy should be high energy to excite the peroxide molecules without overheating the pulp of the tooth. Lights are typically within the blue light spectrum as this has been found to contain the most effective wavelengths for initiating the hydrogen peroxide reaction. A power bleaching treatment typically involves isolation of soft tissue with a resin-based, light-curable barrier, application of a professional dental-grade hydrogen peroxide whitening gel (25-38% hydrogen peroxide), and exposure to the light source for 6–15 minutes. Recent technical advances have minimized heat and ultraviolet emissions, allowing for a shorter patient preparation procedure. Most power teeth whitening treatments can be done in approximately 30 minutes to one hour, in a single visit to a dental professional.
At-home whitening methods include gels, chewing gums, rinses, toothpaste, paint-on films, and whitening strips. Most over-the-counter methods utilize either carbamide peroxide or hydrogen peroxide. Although there is some evidence that such products will whiten the teeth compared to placebo, the majority of the published scientific studies were short term and are subject to a high risk of bias as the research was sponsored or conducted by the manufacturers. There is no long term evidence of the effectiveness or potential risks of such products. Any demonstrable difference in the short term efficiency of such products seems to be related to the concentration of the active ingredient.
Toothpaste which are advertised as “whitening” rarely contain carbamide peroxide, hydrogen peroxide or any other bleaching agent. Rather, they are abrasive (usually containing alumina, dicalcium phosphate dehydrate, calcium carbonate or silica, intended to remove surface stains from the tooth surface. Sometimes they contain enzymes purported to break down the biofilm on teeth. The Whitening Evo Toothpaste can be found in The Smile Bar. Brilliant Smile has developed this exclusive gel-based toothpaste that effectively makes your teeth whiter without damaging abrasives, and contributes to better oral health. Using it twice daily effectively prevents the formation of discoloration and stains on the teeth, and protects teeth against cavities, plaque and tooth sensitivity.
One purported method of naturally whitening the teeth is through the use of malic acid.The juice of apples, especially green apples, contains malic acid. On the other hand, excessive consumption of acidic beverages will slowly dissolve the enamel layer, making the underlying yellower dentin show through more noticeably, leading to darkening of the tooth’s appearance. One study indicates that malic acid is a weak tooth whitening agent.
Apples, celery, and carrots may help whiten teeth as they act like natural stain removers by increasing saliva production (the mouth’s self-cleaning agent) and mechanically cleanse scrub the teeth clean. They help maintain a fresh breath by killing bacteria that produces halitosis.
(Sources: “Statement on the Safety and Effectiveness of Tooth Whitening Products”. American Dental Association.)back