Tooth whitening
[1] Whitening is often desirable when teeth become yellowed over time for a number of reasons, and can be achieved by changing the intrinsic or extrinsic colour of the tooth enamel.
When it diffuses into the tooth, hydrogen peroxide acts as an oxidising agent that breaks down to produce unstable free radicals.
[5] This can be attributed to secondary dentin formation and thinning of enamel due to tooth wear which contributes to a significant decrease in lightness and increase in yellowness.
[1] In essence, tooth whitening primarily targets those intrinsic stains in which cannot be removed through mechanics such as a debridement (clean) or prophylaxis, in the dental office.
Extrinsic staining, is largely due to environmental factors including smoking, pigments in beverages and foods, antibiotics, and metals such as iron or copper.
Coloured compounds from these sources are adsorbed into acquired dental pellicle or directly onto the surface of the tooth causing a stain to appear.
This will allow the clinician to see if there is any treatment that needs to be done such as restorations to remove cavities, and to assess whether or not the patient will be a good candidate to have the whitening done.
The clinician would then debride (clean) the tooth surface with an ultrasonic scaler, hand instruments, and potentially a prophy paste to remove extrinsic stains as mentioned above.
Before the treatment, the clinician should 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.
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.
[35] A 2015 study showed that the use of a light activator does not improve bleaching, has no measurable effect, and rather is likely to increase the temperature of the associated tissues, resulting in damage.
The patient will need to have a healthy mouth and free of periodontal disease or cavities and to have had a debridement/clean done to remove any tartar or plaque build up.
[1] Tray-based tooth whitening is achieved by wearing a fitted tray containing carbamide peroxide bleaching gel overnight or for two to four hours a day.
[43] Tooth whitening toothpaste that have excessive abrasivity are harmful to dental tissue, therefore baking soda is a desirable alternative.
[43] It also contains acid-buffering components that makes baking soda biologically antibacterial at high concentrations and capable of preventing growth of Streptococcus mutans.
[41] The use of bleach with extremely low pH levels in the tooth whitening procedure may lead to hypersensitive teeth, as it causes the dentinal tubules to open.
[50][51] Potassium nitrate and sodium fluoride in toothpastes are used to ease discomfort following bleaching, however, there is no evidence to suggest that this is a permanent method to eradicate the issue of hypersensitivity.
The temporary burning induced by whitening treatments can be reduced by using custom-made plastic trays or nightguards provided by the dental professional.
Consuming less foods and drinks that cause surface staining of teeth can contribute to attaining a good result from tooth whitening.
[58] A person with bleachorexia will continually seek out for different whitening products, hence, it is recommended that a target shade is agreed upon before starting the treatment procedure to help with this problem.
[67] Erratic or inaccurate use of the bleaching trays could cause harm to the patient such as blistering or sensitivity of the teeth and the surrounding soft tissue.
[70] The downside is that these radicals have certain local harmful effects, such as enamel erosion, changes in the microhardness of the teeth, gum irritation, post-bleaching hypersensitivity, and burning sensations.
[74] In the clinical application of PAP for tooth whitening, oxidation reactions also occur, and color molecules are bleached through chemical-physical processes.
[76] However, the International Agency of Research on Cancer (IARC) has concluded that there is insufficient evidence to prove that hydrogen peroxide is a carcinogen to humans.
The results indicated that the oral health products that contain or release hydrogen peroxide up to 3.6% will not increase the cancerous risk of an individual,[78] hence, it is safe to use in moderation.
Various methods may be employed to prolong the treatment results, such as:[citation needed] Teeth whitening remedies have been present since ancient times.
[84] In the late 1960s, Dr William Klusmeier, an Orthodontist from Fort Smith, Arkansas, introduced the custom tray bleaching.
[citation needed] As per European Council guidelines, only a certified dental professional can lawfully give tooth whitening products utilizing 0.1–6% hydrogen peroxide, provided the patient is 18 years of age or older.
"[87] A public attitudes survey, conducted by the GDC, showed that 83% of people support "policies of regulating tooth whitening to protect patient safety and prosecuting illegal practice.
[45] According to research, tooth whitening can produce positive changes in young participants' Oral Health Related Quality of Life (OHRQoL) in aesthetic areas such as smiling, laughing, and showing teeth without embarrassment.
