Tooth Whitening

Tooth whitening is the use of bleaching agents to lighten the colour of teeth. The normal colour of tooth enamel (the hard outer surface of each tooth) varies, with most teeth ranging from off-white to light yellow. Teeth may be discoloured by various factors including:
• surface stains due to lifestyle (for example, smoking, coffee, tea or red wine)
• age
• poor oral hygiene, with irregular brushing and flossing
• certain medicines, for example, tetracycline (antibiotic)
• dental problems such as tooth decay, tooth injuries, thin enamel, tartar (hardened plaque, also called calculus) and old fillings, which can turn teeth yellowish, brown, grey or black
• excessive fluoride, which can discolour and mottle teeth if taken during early childhood.
Teeth discoloured by surface stains or age usually respond best to whitening treatment.
Only your dentist is qualified to assess you correctly and, if applicable, provide you with a bleaching treatment to ensure the best result for you.
Your Dental and Medical History
Tell your dentist your dental and medical history. This confidential information helps the dentist to diagnose the cause of your tooth discolouration and may influence decisions on bleaching products.
Your dentist will inspect your teeth and may take X-ray films. Sometimes, a patient has other dental problems such as decay or gum disease that must be treated first.
You will need to talk to your dentist about these additional treatments and the estimated costs.
Not everyone is a good candidate for tooth whitening. Factors that could make this treatment unsuitable include:
• discolouration caused by medicines or fluoride
• tooth sensitivity to hot and cold food and drink
• defective or absent tooth enamel
• habitual use of tobacco products such as cigarettes, cigars or chewing tobacco
• gum disease (periodontitis)
• habitual use of some alcoholic drinks
• presence of dentures, dental implants, crowns, veneers or fillings
• young age, if permanent teeth are still developing
• pregnancy or breast feeding.
Talk to your dentist
The aim of this page is to provide general information. It is not a substitute for advice from your dentist and does not contain everything known about tooth whitening or every possible side effect of treatment.
Use this page only in consultation with your dentist. If you have any concerns, discuss them with your dentist.
Realistic expectation: Most patients have whiter teeth following treatment. However, your teeth may not become as white as you had hoped. Teeth yellowed or darkened by medicines, trauma or disease respond unpredictably, and the dentist cannot anticipate if the treatment will work or to what degree.
Results from most whitening treatments last between one and three years, and most treatments can be reapplied after one to three years. Depending on a person's smoking, drinking and oral hygiene habits, the results may last for only a few months.
Discuss your expectations with your dentist to be sure you have a realistic understanding of the treatment's limitations.
Consent form: Your dentist may ask you to sign a consent form before performing certain types of dental treatment. Read it carefully.
If you have any questions about the consent form, treatment risks or anything else, ask your dentist.
Professional Treatments
Various professional whitening treatments are available. Your dentist will discuss the best treatment for you depending on factors including your dental history, the causes of your tooth discolouration, and the degree of discolouration. Sometimes, the dentist may suggest a combination of treatments. Your dentist may give you anti-inflammatory medicine beforehand to reduce the risk of discomfort. Your dentist may conclude with a topical fluoride treatment and/or a tooth-remineralising treatment to strengthen tooth enamel and reduce the risk of sensitivity to hot and cold.
Light-activated and laser bleaching
Your dentist protects your lips and gums with rubber seals or gel, then applies a bleaching agent to tooth surfaces. A high intensity light or a laser is shone into your mouth to quicken the whitening process. This bleaching takes about one hour to complete in a single session.
Multiple sessions may be needed or may need to be augmented with the tray method of application.
Good oral hygiene, regular professional cleaning and occasional bleaching will keep your teeth whiter for longer. Your smile may benefit from other restoration treatments such as veneers, replacement crowns or fillings.
Internal bleaching of a root-filled tooth
Your dentist may suggest internal bleaching for a tooth that has turned dark after root canal treatment. Your dentist drills a small hole into the back of the tooth, removes some of the filling from the tooth's root canal, and inserts the bleaching product. The hole is closed with a temporary filling. You will need to return to your dentist in about one week to have the bleaching product and temporary filling removed. To achieve a whiter tooth, the procedure may have to be done again. When treatment is complete, your dentist removes the bleaching product and seals the hole with a permanent filling. In some cases, your dentist may suggest both internal and external bleaching. As veneers, crowns and other techniques have some effective and attractive, some patients prefer these options.
Bleaching trays
Your dentist takes a mould of your teeth to make plastic trays that have a custom fit, then gives you tubes of bleaching gel and instructions. You may wear the gel-filled trays at home anywhere between an hour and overnight. Most people will need to wear the mouth trays every day for two to four weeks.
Possible Complications
All dental treatments carry some degree of risk. It is not usual for the dentist to outline every possible, rare complication. However, it is important that you have enough information to fully weigh up the risks, benefits and limitations of treatment. There may be other side effects not listed here. Side effects of tooth whitening may include:
• tooth discomfort or pain
• sensitivity to hot and cold
• short-term sensitivity to air against the teeth
• sore and irritated gums or inner cheeks
• whitened patches on the gum line (typically only with higher concentrations of bleach)
• mouth ulcers
• sore throat
• nausea, if the bleaching agent is accidentally swallowed.
Side effects tend to be mild and usually do not require treatment. However, see your dentist if side effects do not resolve within a few days.
Some side effects are easily treated. For example, topical fluoride applied by your dentist or brushing with toothpaste made for "sensitive teeth" can minimise thermal sensitivity. Pain relievers can ease discomfort.
Over-the-counter kits are cheaper than professional bleaching, but any damage they cause may be expensive to repair. For example, some bleaching products contain acids that can dissolve tooth enamel. Unsupervised, long-term or repeated use of over-the-counter kits increases the risk of such side effects. Always consult your dentist beforehand, and carefully follow the manufacturer's instructions to minimise any side effects.
If you have any side effects not listed here, tell your dentist.
Over-the-counter treatments
These include whitening toothpaste and bleaching kits. Whitening toothpaste contains abrasives, mild bleaches or both that usually are effective only for surface stains such as coffee or red wine.
Various bleaching kits available from your pharmacist include:
• sticky strips worn against the teeth
• special "paint" applied with a brush
• "one-size-fits-all" plastic tray that are filled with bleaching gel. Depending on instructions, you use the bleaching kit for a certain period of time.
• surface stains due to lifestyle (for example, smoking, coffee, tea or red wine)
• age
• poor oral hygiene, with irregular brushing and flossing
• certain medicines, for example, tetracycline (antibiotic)
• dental problems such as tooth decay, tooth injuries, thin enamel, tartar (hardened plaque, also called calculus) and old fillings, which can turn teeth yellowish, brown, grey or black
• excessive fluoride, which can discolour and mottle teeth if taken during early childhood.
Teeth discoloured by surface stains or age usually respond best to whitening treatment.
Only your dentist is qualified to assess you correctly and, if applicable, provide you with a bleaching treatment to ensure the best result for you.
Your Dental and Medical History
Tell your dentist your dental and medical history. This confidential information helps the dentist to diagnose the cause of your tooth discolouration and may influence decisions on bleaching products.
Your dentist will inspect your teeth and may take X-ray films. Sometimes, a patient has other dental problems such as decay or gum disease that must be treated first.
You will need to talk to your dentist about these additional treatments and the estimated costs.
Not everyone is a good candidate for tooth whitening. Factors that could make this treatment unsuitable include:
• discolouration caused by medicines or fluoride
• tooth sensitivity to hot and cold food and drink
• defective or absent tooth enamel
• habitual use of tobacco products such as cigarettes, cigars or chewing tobacco
• gum disease (periodontitis)
• habitual use of some alcoholic drinks
• presence of dentures, dental implants, crowns, veneers or fillings
• young age, if permanent teeth are still developing
• pregnancy or breast feeding.
Talk to your dentist
The aim of this page is to provide general information. It is not a substitute for advice from your dentist and does not contain everything known about tooth whitening or every possible side effect of treatment.
Use this page only in consultation with your dentist. If you have any concerns, discuss them with your dentist.
Realistic expectation: Most patients have whiter teeth following treatment. However, your teeth may not become as white as you had hoped. Teeth yellowed or darkened by medicines, trauma or disease respond unpredictably, and the dentist cannot anticipate if the treatment will work or to what degree.
Results from most whitening treatments last between one and three years, and most treatments can be reapplied after one to three years. Depending on a person's smoking, drinking and oral hygiene habits, the results may last for only a few months.
Discuss your expectations with your dentist to be sure you have a realistic understanding of the treatment's limitations.
Consent form: Your dentist may ask you to sign a consent form before performing certain types of dental treatment. Read it carefully.
If you have any questions about the consent form, treatment risks or anything else, ask your dentist.
Professional Treatments
Various professional whitening treatments are available. Your dentist will discuss the best treatment for you depending on factors including your dental history, the causes of your tooth discolouration, and the degree of discolouration. Sometimes, the dentist may suggest a combination of treatments. Your dentist may give you anti-inflammatory medicine beforehand to reduce the risk of discomfort. Your dentist may conclude with a topical fluoride treatment and/or a tooth-remineralising treatment to strengthen tooth enamel and reduce the risk of sensitivity to hot and cold.
Light-activated and laser bleaching
Your dentist protects your lips and gums with rubber seals or gel, then applies a bleaching agent to tooth surfaces. A high intensity light or a laser is shone into your mouth to quicken the whitening process. This bleaching takes about one hour to complete in a single session.
Multiple sessions may be needed or may need to be augmented with the tray method of application.
Good oral hygiene, regular professional cleaning and occasional bleaching will keep your teeth whiter for longer. Your smile may benefit from other restoration treatments such as veneers, replacement crowns or fillings.
Internal bleaching of a root-filled tooth
Your dentist may suggest internal bleaching for a tooth that has turned dark after root canal treatment. Your dentist drills a small hole into the back of the tooth, removes some of the filling from the tooth's root canal, and inserts the bleaching product. The hole is closed with a temporary filling. You will need to return to your dentist in about one week to have the bleaching product and temporary filling removed. To achieve a whiter tooth, the procedure may have to be done again. When treatment is complete, your dentist removes the bleaching product and seals the hole with a permanent filling. In some cases, your dentist may suggest both internal and external bleaching. As veneers, crowns and other techniques have some effective and attractive, some patients prefer these options.
Bleaching trays
Your dentist takes a mould of your teeth to make plastic trays that have a custom fit, then gives you tubes of bleaching gel and instructions. You may wear the gel-filled trays at home anywhere between an hour and overnight. Most people will need to wear the mouth trays every day for two to four weeks.
Possible Complications
All dental treatments carry some degree of risk. It is not usual for the dentist to outline every possible, rare complication. However, it is important that you have enough information to fully weigh up the risks, benefits and limitations of treatment. There may be other side effects not listed here. Side effects of tooth whitening may include:
• tooth discomfort or pain
• sensitivity to hot and cold
• short-term sensitivity to air against the teeth
• sore and irritated gums or inner cheeks
• whitened patches on the gum line (typically only with higher concentrations of bleach)
• mouth ulcers
• sore throat
• nausea, if the bleaching agent is accidentally swallowed.
Side effects tend to be mild and usually do not require treatment. However, see your dentist if side effects do not resolve within a few days.
Some side effects are easily treated. For example, topical fluoride applied by your dentist or brushing with toothpaste made for "sensitive teeth" can minimise thermal sensitivity. Pain relievers can ease discomfort.
Over-the-counter kits are cheaper than professional bleaching, but any damage they cause may be expensive to repair. For example, some bleaching products contain acids that can dissolve tooth enamel. Unsupervised, long-term or repeated use of over-the-counter kits increases the risk of such side effects. Always consult your dentist beforehand, and carefully follow the manufacturer's instructions to minimise any side effects.
If you have any side effects not listed here, tell your dentist.
Over-the-counter treatments
These include whitening toothpaste and bleaching kits. Whitening toothpaste contains abrasives, mild bleaches or both that usually are effective only for surface stains such as coffee or red wine.
Various bleaching kits available from your pharmacist include:
• sticky strips worn against the teeth
• special "paint" applied with a brush
• "one-size-fits-all" plastic tray that are filled with bleaching gel. Depending on instructions, you use the bleaching kit for a certain period of time.