Tooth Discolouration and staining is primarily due two sources of stain:
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.
1) Extrinsic staining
Is largely due to environment 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.
Extrinsic staining may be removed through various treatment methods:
Includes the removal of extrinsic staining using a slow-speed rotary hand piece and a rubber cup with abrasive paste mostly containing fluoride.
Allows a dental professional to make use of an instrument (called as Airflow) which emits a powder, water and compressed
Air to remove biofilm, and extrinsic staining. This method can only be undertaken in a dental office, not at home.
There are many available on the market that implement both peroxide as well as abrasive particles such as silica gel to help remove extrinsic stains while the peroxide acts on intrinsic staining.
2) Intrinsic Staining
Intrinsic staining primarily occurs during the tooth development either before birth or at early childhood as the age of the person increases, the teeth can also appear yellower over time. Below are examples of intrinsic sources of stains:
• Tooth wear and ageing
• Dental caries
• Restorative material
• Dental trauma
• Enamel hyperplasia
• Pulpal hyperemia
• Dentinogenesis imperfecta (Hereditary dentin defect)
• Amelogenesis imperfecta (Hereditary enamel defect)
• Tetracycline and minocycline
Ingestion during the years of tooth development causes
Yellow-green discoloration (Antibiotics)
• Porphyria (A rare metabolic disorder)
• Alkaptonuria (Metabolic disorder)
• Hemolytic disease of the newborn
• Root resorption
Tooth whitening can be achieved by either changing the intrinsic colour or by removing and controlling the formation of extrinsic stains.
The chemical degradation of the chromogens within or on the tooth is termed as Bleaching.
Hydrogen peroxide (H2o2) is the active ingredient most commonly used in whitening products and is delivered as either hydrogen peroxide
or Carbamide peroxide.
For whitening treatment to be successful, dental professionals should correctly diagnose the type, intensity and location of the tooth Discolouration. Time exposure and the concentration of the bleaching compound, determines the tooth whitening endpoint.
Prior to proceeding to tooth whitening alternatives, it is advised that the patient comes into the dental office to have a comprehensive oral examination and clean the tooth surface with an ultrasonic scaler, hand instrument, and potentially on Airflow or a prophy paste to remove extrinsic stains as mentioned above.
There are three basic methods for tooth whitening:
1) Internal bleaching
2) In-office bleaching
3) At home bleaching
1) Internal bleaching
The internal bleaching is used to whiten tooth discoloration after the root canal.
A way around this is by sealing off the bleaching agent inside the tooth itself and replacing it every few weeks until the desired shade has been achieved.
2) In-office bleaching
The whitening shade guides are used to measure tooth colour. These shades determine the effectiveness of the whitening procedure, which may vary from two to seven shades. These shades may be reached after a single in office appointment, or may take longer, depending on the individual. The effects of bleaching can last for several months, but may vary depending on the life style of the patient.
In-chair whitening is faster and more effective in comparison to the take home bleaching options.
At Amirad Family Dentistry, Dr. Faridrad also make custom bleaching trays for you, which can take up to a week to create, so that after the whitening treatment is completed, you are able to use these trays in the future for maintenance of your bleaching with at home kits or for the use of desensitizing products.
In-office bleaching procedures generally use a light-cured protective layer that is carefully painted on the gum and papilla.
The bleaching agent is either carbamide peroxide or hydrogen peroxide. Bleaching agents are only allowed to be given by dental practitioners, dental therapists, and dental hygienists.
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.
Power or light-.accelerated bleaching uses light energy which is intended to accelerate the process of bleaching in dental office. Different types of energy can be used in this procedure, with the most common being halogen, LED, or Laser.
The ideal source of energy should be high energy to excite the peroxide molecules without over heating 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.
Laser acts as an activator, enhancing the bleaching effect of a special gel, allowing maximum results to be obtained over a short period of time. A laser teeth whitening treatment takes about an hour in the dental office and costs vary but tend to be higher than other methods.
It is recommended to avoid smoking, drinking red wine, eating or drinking any deeply coloured foods after this as the teeth may stain considerably straight after treatment.
3) At home
At home tooth whitening products are available from dentists or over the counter(OTC).
OTC products can be used for milder cases of tooth staining.
a) Strips and Gels
The plastic whitening strips contain a thin layer of peroxide gel and are shaped to fit the buccal/ labial surface of teeth.
The strips are typically applied twice daily for 30 minutes for 14 days.
Whitening gels contain peroxide and are applied onto the tooth surface with a small brush twice a day for 14 days.
Whitening rinses work by reaction of the oxygen sources such as hydrogen peroxide within the rinse and the chromogens on or within the tooth. It is recommended to use twice a day, rinsing for one minute. to see an improvement in shade colour, it can take up to three months.
Whitening toothpastes are different to regular toothpastes in that they contain higher amounts of abrasives and detergents to be more effective at removing tougher stains.
Some whitening toothpastes contain low concentrations of carbamide peroxide or hydrogen peroxide which help lighten tooth colour. With continuity of use over time, tooth colour can lighten by one or two shades.
Tray-based tooth whitening is achieved by wearing a fitted tray containing carbamide peroxide bleaching gel over night or for two to four hours a day. If manufacturer’s instructions are followed, tooth whitening can occur within three days and lighten teeth by one or two shades. This type of tooth whitening is available over-the-counter and professionally from an oral health professional.
Baking soda is a safe, low abrasive, and effective stain removal and tooth whitening toothpaste. Tooth whitening toothpaste that have excessive abrasivity are harmful to dental tissue, therefore baking soda is a desirable alternative. It also contains acid-buffering components that makes baking soda biologically antibacterial at high concentrations and capable of preventing growth of streptococcus mutans.
Baking soda might be useful for caries-prone patients as well as those who wish to have whiter teeth.
Tooth whitening maybe undertaken for a variety reasons, but whitening may also be recommended to some individuals by dental professionals
• Intrinsic tooth staining
• Dental fluorosis
• Endodontic treatment (internal bleaching)
• Tetracycline staining
Some groups are advised to carry out tooth whitening with caution as they maybe at higher risk of adverse effects.
• Patients with unrealistic expectations
• Allergy to peroxide
• Cracks or exposed dentine
• Pre-existing sensitive teeth
• Enamel development defects
• Acid erosion
• Receding gums and yellow roots
• Sensitive gums
• Defective dental restorations
• tooth decay-white-spot decalcification maybe highlighted and become more noticeable directly following a whitening process
• Active periapical pathology
• Untreated periodontal disease
• Pregnant and lactating women
• Children under age of 16. This is because the pulp chamber is enlarged until this age which could irritate the pulp or cause it to become sensitive.
• Persons with visible white fillings or crowns.
Tooth whitening does not change the color of filling and other restorative materials.
Bleaching materials are only effective on natural tooth structure.
There are some questions you may ask!
• What is teeth whitening procedure like?
• How is tooth sensitivity managed during teeth whitening treatment?
• How long do teeth whitening results last?
• How much does teeth whitening cost?