WHAT IS TEETH WHITENING?
Teeth whitening is a cosmetic dental procedure designed to lighten the colour of your teeth and remove stains or discoloration, enhancing the overall appearance of your smile. It works by breaking down stains on the surface or within the enamel using bleaching agents such as hydrogen peroxide or carbamide peroxide.
Common Misconceptions About Teeth Whitening
One common misconception is that teeth whitening will result in perfectly white teeth. However, it’s important to understand that natural teeth are not pure white; they have subtle tones of yellow, grey, or off-white. Teeth whitening can only enhance the natural shade of your teeth, not alter their inherent colour entirely.
The extent of whitening depends on several factors, including:
At Tooth Angels Dental Surgeons, we often use a tool called a shade guide to determine the colour of your teeth. The guide shown above is a commonly used example. It helps match the colour of fillings to your natural teeth, ensuring that the restorations appear seamless and “invisible.” Dentists also use the shade guide to assess the current colour of your teeth and predict the potential shade achievable after whitening.
The shade guide categorises tooth colours as follows:
The numbers (1–4) indicate the intensity of the colour, with “1” being the lightest. B1 represents the whitest shade natural teeth can achieve. Even at this lightest shade, natural teeth typically retain a slight yellow undertone.
So remember, you will not be able to achieve a colour whiter than the natural shade of your teeth through whitening - you can only achieve perfectly white teeth, known as the Hollywood Smile, if you use veneers.
The extent of whitening depends on several factors, including:
- The natural shade of your teeth.
- The type and depth of the stains (e.g., surface stains from coffee vs. deeper intrinsic stains caused by medications or trauma).
- The method of whitening used (in-office, take-home kits, or over-the-counter products).
At Tooth Angels Dental Surgeons, we often use a tool called a shade guide to determine the colour of your teeth. The guide shown above is a commonly used example. It helps match the colour of fillings to your natural teeth, ensuring that the restorations appear seamless and “invisible.” Dentists also use the shade guide to assess the current colour of your teeth and predict the potential shade achievable after whitening.
The shade guide categorises tooth colours as follows:
- A: Reddish-brown
- B: Reddish-yellow
- C: Grey
- D: Reddish-grey
The numbers (1–4) indicate the intensity of the colour, with “1” being the lightest. B1 represents the whitest shade natural teeth can achieve. Even at this lightest shade, natural teeth typically retain a slight yellow undertone.
So remember, you will not be able to achieve a colour whiter than the natural shade of your teeth through whitening - you can only achieve perfectly white teeth, known as the Hollywood Smile, if you use veneers.
What Causes Stains And Discolouration?
Many patients ask, "Why are my teeth still yellow even though I brush regularly?" The answer lies in the fact that yellow teeth can result from factors beyond dental hygiene. Tooth discolouration typically falls into three categories:
Extrinsic Causes
While maintaining good oral hygiene can reduce the occurrence of extrinsic stains, it cannot alter the natural shade of your teeth, which is determined by underlying factors. Regular dental visits and proper care are key to keeping extrinsic stains under control.
Extrinsic stains are external stains that appear on the surface of your teeth. These stains are caused by:
Managing Extrinsic Stains
- Frequent consumption of dark-coloured beverages: Drinks like coffee, tea, and red wine are common culprits for staining teeth over time.
- Smoking: Cigarettes contain tar, a dark brown substance that adheres to tooth surfaces, causing discolouration.
- Poor brushing habits: Inadequate oral hygiene can lead to yellowing or darkening of teeth due to the accumulation of yellow plaque or dark-brown calculus (hardened plaque).
Managing Extrinsic Stains
- Professional Cleaning: These stains can be effectively removed during regular dental cleaning appointments.
- Whitening Toothpaste: Toothpaste with abrasive particles can help rub away surface stains. However, it’s important to note that whitening toothpaste only removes external stains and does not change the base colour of your teeth.
Intrinsic Causes
Intrinsic stains originate within the tooth and cannot be removed with cleaning or abrasive toothpaste. Here are five common causes of internal tooth discolouration:
Excessive Fluoride Exposure
- Overuse of fluoride before the age of 8 can lead to white, yellow, or brown spots on the teeth, known as dental fluorosis.
- These stains occur when the enamel-forming cells are disrupted during tooth development.
Root Canal Treatment or
Non-Vital Teeth
- Teeth may turn dark grey or brown after a root canal treatment or if the tooth becomes non-vital (dies).
- The discolouration occurs due to internal bleeding or decomposition of the tooth pulp.
Traumatic Injury to a Tooth
- Trauma to a tooth can cause it to appear reddish-brown or pink due to internal bleeding or damage to the pulp.
- Over time, the discolouration may darken as the tissue inside the tooth deteriorates.
Tetracycline Exposure
- If a mother took tetracycline antibiotics during pregnancy or if a child took them before the age of 8, it can cause teeth to develop dark-brown or grey discolouration.
- These stains often appear in bands, reflecting the time the antibiotic was taken during tooth development.
Heavy Smoking
- How Smoking Stains Teeth: Prolonged smoking causes tar and nicotine to seep into the enamel’s tiny tubules, resulting in permanent yellow, brown, or black stains, especially near the gumline (cervical region). These stains are difficult to remove without professional treatment.
- Treatment and Prevention: Professional interventions like scaling, polishing, teeth whitening, or veneers can address smoking stains.
Managing Intrinsic Stains
Intrinsic discolouration typically requires professional treatments such as:
Treatment for Smoking Stains
Removing stains caused by heavy smoking often requires professional dental interventions:
However, long-term solutions often require addressing the underlying smoking habit to prevent recurrence.
For intrinsic stains, it is best to consult your dentist for the most suitable treatment based on the cause and severity of the intrinsic stains.
Intrinsic discolouration typically requires professional treatments such as:
- Teeth Whitening: In-office or take-home whitening treatments may lighten some internal stains.
- Veneers or Crowns: Severe discolouration may require covering the affected teeth with veneers or crowns to restore aesthetics.
- Internal Bleaching: In cases like root canal discolouration, dentists may bleach the tooth from the inside.
Treatment for Smoking Stains
Removing stains caused by heavy smoking often requires professional dental interventions:
- Scaling and Polishing: Removes surface stains and tartar near the gumline.
- Teeth Whitening: In-office or take-home whitening systems can lighten extrinsic stains.
- Veneers or Crowns: For deeply stained or damaged teeth, veneers or crowns may be necessary to restore aesthetics.
- Lifestyle Changes: Quitting smoking is essential to prevent further staining and improve overall oral health.
- Regular dental check-ups and cleanings, combined with effective at-home oral care, can help manage and minimise the impact of smoking on teeth.
However, long-term solutions often require addressing the underlying smoking habit to prevent recurrence.
For intrinsic stains, it is best to consult your dentist for the most suitable treatment based on the cause and severity of the intrinsic stains.
Age-Related Causes
The outermost layer of our teeth, enamel, is a translucent bluish layer. Beneath it lies the dentine, which gives teeth their yellowish colour.
The appearance of teeth depends on the thickness and opacity of the enamel—thicker enamel makes teeth look whiter.
Over time, enamel naturally thins due to factors like wear, acid erosion, or teeth grinding (parafunction), exposing more of the dentine.
This thinning makes teeth appear yellower and, in some cases, even brown.
The appearance of teeth depends on the thickness and opacity of the enamel—thicker enamel makes teeth look whiter.
Over time, enamel naturally thins due to factors like wear, acid erosion, or teeth grinding (parafunction), exposing more of the dentine.
This thinning makes teeth appear yellower and, in some cases, even brown.
Frequently Asked Questions About Teeth Whitening
Teeth whitening is generally painless. Some people may experience mild sensitivity after the procedure, which usually lasts for 24 hours. Using desensitising toothpaste before and after can help reduce sensitivity.
Yes, professional teeth whitening is safe. Dentists use non-acidic, regulated products and take precautions to protect gums. Over-the-counter kits may not be as safe, so consult a dentist for optimal results.
Not everyone is a candidate for teeth whitening. People with gum disease, tooth decay, or intrinsic stains may need other treatments, such as veneers or internal bleaching. Your dentist will assess your suitability.
Teeth whitening results can last between 6 months to 2 years, depending on lifestyle and oral hygiene. Avoiding staining foods and beverages, along with regular cleanings, helps maintain your bright smile.
After whitening, avoid staining foods and drinks like coffee, tea, red wine, and dark sauces for 48 hours. Smoking and coloured foods can also stain freshly whitened teeth. Stick to a "white diet" temporarily for best results.
Teeth whitening works well for surface stains but is less effective for deep intrinsic stains caused by trauma or medications like tetracycline. For stubborn stains, dentists may recommend veneers or other treatments.
Professional teeth whitening is safe to repeat every 6–12 months, depending on your habits and dentist’s recommendations. Avoid over-whitening, as it can cause sensitivity and weaken enamel. Your dentist would be able to advise you on the usage of home kit frequency.
No, teeth whitening does not change the colour of crowns, veneers, or fillings. If restorations become mismatched, your dentist may recommend replacing them for a uniform look.
Yes, professional home whitening kits with custom-fitted trays are available. These trays are made from impressions of your teeth, ensuring even application of the whitening gel for safe, gradual results.
Professional teeth whitening done by the dentist or dentist prescribed home kits does not damage enamel. The whitening gel targets stains without affecting the tooth structure. Avoid unregulated products, which may harm your enamel.
Teeth whitening enhances your natural shade but cannot make teeth "paper-white." Factors like enamel thickness, dentine colour, and age influence how bright your teeth can become.
Whitening is not advised while wearing braces, as the brackets cover parts of the teeth, leading to uneven results. It’s best to wait until after braces are removed.
