The colour of teeth can change gradually due to ageing, diet, tobacco use, medications and other factors. Professional teeth whitening is one option for people who would like to lighten the appearance of their natural teeth.
Whitening is an elective treatment and is not suitable or necessary for everyone. Before treatment, a dental practitioner should assess the cause of the discolouration, examine the teeth and gums and explain the likely benefits, risks and limitations.
Why do teeth change colour?
Tooth colour varies naturally between individuals. Teeth are not necessarily unhealthy because they appear cream, yellow or darker than expected.
Discolouration may be described as either extrinsic or intrinsic.
Extrinsic discolouration
Extrinsic stains develop on the external surface of the teeth. They may be associated with:
- Coffee and tea
- Red wine
- Coloured foods
- Tobacco use
- Plaque or calculus
- Certain mouth rinses or medications
Some surface stains may improve with professional cleaning. Whitening may be considered if further lightening is desired after the teeth have been assessed.
Intrinsic discolouration
Intrinsic colour changes occur within the tooth and may be associated with:
- Natural ageing
- Previous dental trauma
- Tooth development
- Certain medications, including tetracycline taken while teeth were developing
- Changes within a tooth following nerve damage
- Some developmental dental conditions
Intrinsic discolouration may respond less predictably to whitening. Depending on the cause, alternative treatment or further investigation may be required.
How does ageing affect tooth colour?
The outer enamel layer can become thinner or more translucent over time, allowing more of the naturally darker dentine beneath it to show through. Years of exposure to coloured foods, drinks and tobacco may also contribute to surface staining.
Whitening can lighten some types of discolouration, but it cannot reverse ageing or guarantee that a person will look younger. The degree of change varies according to the starting shade, cause of the discolouration and response of the teeth.
What is professional teeth whitening?
Professional whitening uses a peroxide-based bleaching agent to lighten pigments within natural tooth structure.
Treatment options may include:
- In-chair whitening performed at the dental practice
- Dentist-prescribed take-home whitening
- A combination of in-chair and take-home treatment
The concentration of the whitening agent, application time and number of sessions depend on the product used and the patient’s circumstances.
Whitening should be preceded by a dental examination. Decay, leaking restorations, gum inflammation, cracks, exposed roots or other concerns may need to be managed before bleaching is considered.
In-chair teeth whitening
In-chair whitening involves applying a whitening gel to the teeth while measures are taken to protect the gums and other soft tissues.
Depending on the system, the appointment may involve several applications of whitening gel. Some products are used with a light, while others are chemically activated without one. The presence of a light does not by itself guarantee a better result.
Potential advantages include professional supervision and control over the application of the whitening material. However, sensitivity and gum irritation can still occur, and the final shade cannot be guaranteed.
Take-home whitening prescribed by a dentist
Dentist-prescribed take-home whitening usually involves custom-made trays and a whitening gel selected for the patient.
The trays are designed to hold the material against the teeth while limiting contact with the gums. Patients are instructed how much gel to use, how long to wear the trays and what to do if sensitivity develops.
Treatment generally occurs over several days or weeks. Following the instructions is important because using too much gel or wearing the trays for longer than recommended may increase sensitivity and soft-tissue irritation without necessarily producing a better result.
How is professional whitening different from retail products?
Whitening products sold through pharmacies, supermarkets and online stores vary in their ingredients, concentrations, application methods and quality of fit.
A dental practitioner can examine the cause of the discolouration and identify conditions that may make whitening inappropriate or uncomfortable. Professionally prescribed trays can also be made to fit the individual teeth.
This does not mean that professional treatment is risk-free or that retail products cannot produce any change. Results and adverse effects can occur with either approach.
Products obtained from overseas or unverified online suppliers may not meet Australian requirements. Whitening products should be used only according to their instructions and applicable professional advice.
What results can be expected?
Whitening may lighten some natural teeth, but the amount of change varies. It is not possible to guarantee a particular shade or number of shades.
Results may be affected by:
- The original tooth colour
- The cause and depth of staining
- Previous dental trauma
- Age and enamel thickness
- The whitening system used
- Treatment duration and adherence to instructions
- Ongoing exposure to staining substances
Some teeth may respond unevenly. Existing white spots or colour variations can temporarily become more noticeable during treatment.
Whitening does not change every dental material
Whitening products act on natural tooth structure. They do not predictably change the colour of:
- Porcelain veneers
- Dental crowns
- Composite fillings or bonding
- Implant crowns
- Bridges
- Dentures
Existing restorations may appear darker or different from the whitened teeth. If replacement is being considered for colour matching, the timing, risks and costs should be discussed before whitening begins.
Healthy restorations should not automatically be replaced for cosmetic reasons.
What are the possible risks?
Possible side effects and limitations of teeth whitening include:
- Temporary tooth sensitivity
- Gum, lip or tongue irritation
- Chemical burns if concentrated gel contacts soft tissues
- Uneven or incomplete whitening
- Increased visibility of existing white spots
- Colour differences between natural teeth and restorations
- Temporary dehydration that makes teeth initially appear lighter
- Discomfort around cracks, decay, exposed roots or leaking restorations
- Relapse or gradual darkening after treatment
Sensitivity can occasionally be significant. Treatment may need to be shortened, paused or discontinued.
Contact your dental practitioner if you develop severe or persistent pain, prolonged gum irritation, ulcers or an unexpected colour change in an individual tooth.
Who may need further assessment before whitening?
Additional assessment may be needed when there is:
- Tooth decay
- Gum disease
- Significant sensitivity
- Cracked or heavily worn teeth
- Exposed tooth roots
- Extensive crowns, veneers or fillings
- Discolouration affecting only one tooth
- A history of dental trauma
- Discolouration that may not respond predictably to bleaching
- Pregnancy or breastfeeding
- An allergy or sensitivity to product ingredients
A single dark tooth can sometimes indicate previous trauma or loss of vitality and should be examined rather than simply whitened.
How long does whitening last?
Whitening is not permanent. The colour may gradually change with ageing and exposure to coloured foods, drinks or tobacco.
Some people may consider additional treatment in the future, but repeated whitening should not be undertaken automatically. A dental practitioner can advise whether further treatment is appropriate and how frequently it may be used.
Daily brushing with fluoride toothpaste, cleaning between the teeth and managing surface stains may help maintain oral health and tooth appearance. Whitening does not replace routine dental care.
Questions to ask before whitening
Before deciding whether to proceed, consider asking:
- What is causing my tooth discolouration?
- Is whitening likely to affect this type of staining?
- Are my teeth and gums suitable for treatment?
- What alternatives are available?
- What degree of change might reasonably be expected?
- Could my crowns, veneers or fillings look different afterwards?
- What are the risks in my circumstances?
- What should I do if sensitivity develops?
- What is included in the treatment cost?
- Is future maintenance likely to be required?
Discuss teeth whitening in Perth
To discuss professional teeth whitening, contact Smile Design Studio in Mosman Park, Perth, on (08) 9468 3322 or request a consultation online.
An assessment can help identify the cause of the discolouration and determine whether whitening or another option may be appropriate.
Disclaimer: This information is general in nature and intended for adults. It is not dental advice or a substitute for an individual examination by a registered dental practitioner. Treatment suitability, risks and outcomes vary. No particular shade or duration of result can be guaranteed.
