A recent survey conducted online revealed that about two-thirds of Americans have tried to bleach their teeth using various techniques. By the end of 2010, it was estimated that an average of $15 billion had been used in teeth whitening procedures. Tooth whitening, also known as tooth bleaching is the process of brightening the tooth enamel or removing stains in teeth.
Several factors determine which color of teeth one has. Factors like enamel thickness, absorption, and scattering capacity of the dental tissue, diet, and dentine color affect the color of teeth that one has. An excellent example is an individual who consumes tobacco, coffee, or wine is more likely to have teeth stains than those who do not.
Teeth discoloration occurs due to several factors that are broadly classified into extrinsic and intrinsic factors. Extrinsic factors are those factors that affect the external structure of the teeth due to environmental influence; whereas intrinsic factors affect the internal structures of the teeth. Additionally, intrinsic factors may mean the causes of tooth discoloration are an anomaly that occurs from birth or during the early developmental stages.
Extrinsic Causes of Tooth Staining
Extrinsic teeth stains occur due to environmental factors such as diet. Consuming foods that are rich in tannins like coffee, tea or red wine, tobacco, pigmented beverages and foods, and antibiotics like tetracycline cause tooth discoloration. One of the leading causes of tooth discoloration is the formation of plagues.
A dental plaque is a clear biofilm of living bacteria that starts to form at the base of the tooth close to the gum when one does not brush their teeth. Once the plaque forms, it attracts chromogenic bacteria like Actinomyces and Streptococcus species which facilitates the formation of opaque milk-colored spots on the tooth enamel. Eating high amounts of carbohydrate will aggravate the condition because the carbohydrates ferments, it forms acidic components which facilitate tooth demineralization and formation of opaque lesions.
Neglected plaques over time will calcify to form hard opaque deposits around the teeth starting from the gum line. A calcified dental plaque is known as calculus. The color of the calculus varies from yellow, brown to grey.
Over time, the color of the calculus intensifies, and it becomes more difficult to eliminate the stain. Additionally, metallic salts like iron, copper, nickel, and cadmium can cause tooth discoloration. These metals are found in foods, medicine, or occupational exposure via metal dust inhalation in miners.
The metallic compounds infiltrate the tooth structure and cause permanent tooth discoloration. To avoid extrinsic tooth staining, doctors recommend brushing your teeth at least twice daily using a fluoride-containing toothpaste. Additionally, one can decide to visit the dentist for teeth cleaning and removal of plaques.
Intrinsic Tooth Staining
Intrinsic staining occurs due to developmental tooth anomalies like enamel hypoplasia, pulpal hyperemia, fluorosis, dentinogenesis imperfecta, porphyria, and root resorption. Intrinsic tooth staining can rarely be reversed unless you resolve the underlying cause.
Methods of Teeth Whitening
Most teeth bleaching agents contain hydrogen peroxide, or carbamide peroxide Hydrogen peroxide is a potent oxidizing agent and once it infiltrates the tooth and breaks down into unstable free radicals. The free radicals scavenge for and attach to organic molecules. This causes the heavily pigmented molecules to become less pigmented hence creating a whitening effect.
The techniques used to remove teeth stains are broadly classified into in-office techniques and at-home techniques. Before scheduling for a dental appointment to whiten your teeth, it is essential to visit your dentist for a thorough teeth examination and check-up. This will allow the dentist to assess the etiology of your tooth discoloration, conduct teeth debridement, and offer alternative techniques to whiten your teeth.
In-office Tooth Whitening
The in-office teeth whitening procedures combines both chemical and light-based methods to get the best outcomes. These two methods supplement each other. The light energy used accelerates the degradation of hydrogen peroxide to the free radicals; thus, accelerating the bleaching process.
However, recent studies have revealed that using light with high wavelength has no much implications to the teeth bleaching process, especially when high concentrations of hydrogen peroxide bleaching agents are used. The light energy was found to cause heightened tooth sensitivity and damage the underlying tissue. Therefore, scientists came up with a better technique of using nano-particles catalysts and reduced concentrations of hydrogen peroxide.
The nano-particles act as chemical catalysts that facilitate the rapid degradation of hydrogen peroxide. The second approach of in-office teeth whitening is the internal bleaching, also known as the endodontic treatment. However, this technique calls for the removal of nerve endings via a root canal.
The bleaching agent is administered to the tooth via consecutive treatments until the desired shade is achieved. Later the external tooth structure is sealed.
This technique does not require one to schedule an appointment with a dentist. An individual buys a whitening kit over the counter from the local pharmacy or the doctor’s office. The tooth whitening product is available as strips, gels, and rinses.
Such products contain a low concentration of hydrogen peroxide coupled with a mild abrasive agent. Other people have resolved to modified home-based remedies like using baking soda to whiten their teeth. Although there is no direct proof of this effectively working, it is thought to be useful for the removal of mild stains.
Baking soda is a mild abrasive agent; thus, it is considered a safe method. Baking soda is made up of sodium bicarbonate, which alters the mouth pH, creating an unfavorable environment for bacterial growth, this in turn minimizes plaque formation. Additionally, if baking soda is used in high concentrations, it has antibacterial properties against the colonizing plaque-forming bacteria in the mouth.
The whitening kit contains a whitening toothpaste. A whitening toothpaste differs from other regular toothpaste in that it contains higher concentrations of carbamide peroxide, abrasives, and detergent. This makes it useful in removing the stubborn teeth stains that can not be removed by regular toothpaste.
Tooth bleaching is not a guaranteed safe procedure; if it is done regularly, it may lead to serious adverse effects. These adverse effects include dentine hypersensitivity, weakened dentine, damaged enamel, over-bleaching effects, and uneven results. Dentine hypersensitivity occurs because the bleaching process opens up the dentine tubules; thus on exposure to the slightest cold or hot temperature, an individual will experience sensitivity.
Dentine hypersensitivity is a common side effect after teeth bleaching procedure. Dentist recommends the use of potassium nitrate or sodium fluoride-containing toothpaste to reduce teeth hypersensitivity. Another side effect is irritation of the mucus membrane found in the mouth.
Hydrogen peroxide that is more than 10% in concentration is corrosive and cytotoxic. Alteration of pH in the mouth and chemical burns will irritate the surrounding tissue. In addition, recent studies have revealed that hydrogen peroxide and its related products like carbamide peroxide are carcinogenic.
World Health Organization and FDA released a statement saying that the safe limit concentration of hydrogen peroxide is 3.6% Frequent teeth whitening leads to a chronic unhealthy obsession known as bleachorexia. Blachorexia is considered a psychological disorder similar to body dysmorphic disorder.
An individual diagnosed with bleachorexia will continuously look for ways to whiten their teeth. Dentists are advised to conduct a psychological evaluation of their patient’s expectations before they conduct a tooth whitening procedure on them. Therefore, teeth whitening is not recommended by everyone.
It is contraindicated in lactating or pregnant women, individuals with unrealistic expectations, individuals allergic to peroxide, and patients with underlying teeth conditions like cracks and dental carries. Additionally, individuals with pre-existing tooth sensitivity, enamel damage, and dental fillings are not recommended to undergo a dental whitening procedure.
Now that you have undergone the teeth whitening procedure, what steps should you take to maintain the results?
Experts advise that one should avoid highly pigmented food, especially the first three weeks after the procedure has been done. They should frequently brush and floss their teeth to remove plaques or biofilms. Re-treatment should be done every six months or annually depending on the procedure that was initially done.
It is recommended to take fluid containing highly-pigmented substance or tannin using a straw to minimize its contact with your teeth.