Posted on October 13, 2026

Are your teeth looking more yellow or stained than they used to?

Coffee, tea, smoking and natural ageing can all affect the colour of your smile. If you want a brighter appearance, professional teeth whitening could be worth considering.

Before booking an appointment, you may want to know how the teeth whitening procedure works, how long it takes and whether it causes sensitivity. Understanding each stage can help you feel more comfortable about treatment and choose an option that suits your needs.

At Aldgate Dental Care, we offer professional teeth whitening treatment in London tailored to your dental health and goals. Our dentist will assess your teeth’s condition and gums, explain suitable treatments and discuss the results you can realistically expect.

In this insightful guide, we’ll explore what you need to know about the teeth whitening procedure, its benefits and the aftercare that helps maintain results.

What Is the Teeth Whitening Procedure?

The teeth whitening procedure is a cosmetic dental treatment that uses bleaching agents, such as hydrogen peroxide or carbamide peroxide, to lighten natural tooth colour by breaking down compounds that cause discolouration.

Unlike a scale and polish, which removes plaque, tartar and surface stains, professional whitening targets tooth discolouration.

The procedure typically involves:

  • Dental assessment: Checking your teeth and gums.
  • Whitening treatment: Applying professional gel in-practice or using custom-fitted trays at home.
  • Aftercare advice: Managing sensitivity and maintaining results.

If your teeth look yellow, understanding the causes of yellow teeth and available whitening solutions can help you discuss suitable treatment options with your dentist. Results depend mainly on your natural tooth colour and the cause of discolouration.

Step-by-Step Dentist Teeth Whitening Procedure

The dentist teeth whitening procedure depends on whether you choose in-practice treatment or professional at-home whitening. Both options begin with a dental assessment to determine your suitability.

Step 1: Attend a Dental Consultation

Your dentist checks your teeth’s condition and gums for decay, gum disease, cracks or sensitivity that may need attention before whitening.

During your consultation, your dentist will:

  • Assess your oral health.
  • Discuss your desired tooth shade.
  • Explain suitable treatments, possible side effects and costs.

This helps your dentist recommend a procedure for teeth whitening suited to your needs.

Step 2: Assess Your Tooth Shade and Agree on Your Goal

Your dentist checks your natural tooth colour and the cause of discolouration. Yellow stains may respond well to bleaching, while some grey or brown stains may need a different approach.

Your dentist considers:

  • Your current tooth shade and the cause of staining.
  • Whether in-practice or at-home whitening suits you.
  • The results you can realistically expect.

This assessment helps establish a suitable treatment plan.

Step 3: Prepare Your Teeth for Whitening

Before whitening, your dentist may recommend professional cleaning or treatment for existing dental problems. The preparation depends on your oral health and chosen treatment.

This may involve:

  • Treating dental issues before whitening.
  • Protecting your gums during in-practice treatment.
  • Taking scans or impressions for custom-fitted trays.

These steps help prepare your teeth and protect your gums during the teeth whitening procedure.

Step 4: Apply the Professional Whitening Gel

During the whitening teeth procedure, your dentist applies professional bleaching gel according to the treatment instructions. Some systems use a special light, while others rely on the gel alone.

For at-home whitening, your dentist explains how much gel to use, how long to wear the trays and how often to apply it.

How long does a teeth whitening procedure take?

In-practice treatment may take one to two hours, while at-home whitening can take several days or weeks.

Step 5: Check the Results and Review Your Comfort

After in-practice whitening, your dentist checks the results. The degree of whitening depends on your natural tooth colour and the cause of discolouration.

Possible side effects include:

  • Temporary sensitivity to hot or cold drinks and foods.
  • Mild gum irritation.
  • Discomfort that may require dental advice.

Contact your dentist if symptoms are severe, persistent or concerning. A follow-up may also be arranged for at-home treatment.

Step 6: Follow Your Personalised Aftercare Plan

Aftercare helps maintain your professional teeth whitening results and manage sensitivity. Your dentist may recommend:

  • Limiting strongly coloured foods and drinks for the advised period.
  • Using toothpaste for sensitive teeth if needed.
  • Brushing twice a day daily and cleaning daily between your teeth.
  • Using whitening trays and top-up gel only as directed.

Following this advice supports your oral health and helps maintain your results.

How Does At-Home Professional Teeth Whitening Work?

At-home professional teeth whitening uses custom-fitted trays and dentist-prescribed whitening gel. The process involves three steps:

  • Dental assessment: Your dentist checks your teeth and gums and prepares custom-fitted trays.
  • Treatment instructions: You receive whitening gel and guidance on how much to use and how long to wear the trays.
  • Whitening at home: Follow the prescribed schedule and contact your dentist if you experience significant sensitivity or irritation.

Unlike in-practice whitening, home treatment gradually lightens teeth over several days or weeks. Comparing the different teeth whitening methods can help you discuss the most suitable option with your dentist.

Neither option is automatically best for every patient. Your dental health, preferred pace, budget and desired outcome will help your dentist recommend a suitable treatment.

What Are the Core Benefits of Professional Teeth Whitening?

Professional teeth whitening can lighten stained or discoloured natural teeth and improve your smile. The main benefits of a dentist teeth whitening procedure include:

  • A brighter and confident smile: Professional teeth whitening treatment can reduce stains caused by coffee, tea, tobacco and ageing.
  • Personalised whitening: Your dentist assesses your tooth colour, dental history and sensitivity to recommend a suitable tooth whitening procedure.
  • Professional supervision: A dentist monitors your oral health and advises you on managing sensitivity or gum irritation.
  • Flexible treatment options: Depending on your needs, you may choose in-practice whitening or dentist-prescribed at-home professional teeth whitening.

A dental assessment also helps identify discolouration that may need a different approach, such as a tooth darkened after trauma or root canal treatment. Your dentist can explain the expected results and help you choose the best professional teeth whitening procedure for your needs.

Teeth Whitening Aftercare: How to Maintain Your Results

Your aftercare routine can affect how long your teeth stay bright after whitening. Knowing how long teeth whitening lasts can help you understand what to expect and how to maintain your results.

Follow these aftercare tips to maintain your results and manage sensitivity.

1. Limit Foods and Drinks That Cause Staining

Tea, coffee, red wine and dark sauces can stain your teeth over time. Your dentist may advise avoiding them for a short period after whitening. Drinking water regularly after meals can help wash away some staining substances.

2. Manage Tooth Sensitivity

Your teeth may feel sensitive to hot or cold drinks and foods after whitening. Try toothpaste for sensitive teeth and avoid anything that triggers discomfort. If sensitivity is severe or lasts longer than expected, contact your dentist.

3. Keep Up With Brushing and Flossing

Brush twice daily without fail with fluoride toothpaste and clean between your teeth. This helps you prevent plaque build-up and keeps your teeth and gums healthy. Regular dental check-ups and hygiene appointments can also help remove plaque and tartar.

4. Avoid Smoking and Tobacco Products

Smoking and tobacco use can cause dull yellow or brown stains on your teeth. Cutting down or stopping can help reduce future staining and improve your oral health.

5. Use Whitening Top-Ups as Recommended

Your whitening results may gradually fade over time. If you want to maintain your tooth shade, ask your dentist whether top-up treatment is suitable. Use only the recommended whitening gel and trays, following the prescribed schedule. Whitening too often can increase sensitivity and irritate your gums.

Does Teeth Whitening Work for Everyone?

Professional teeth whitening can improve many types of discolouration, but results depend on your tooth colour and dental health.

Teeth whitening may work well for:

  • Yellow teeth: Often caused by ageing, coffee or tea.
  • Surface stains: Frequently linked to food, drinks and tobacco.
  • Natural discolouration: Some cases respond well to professional whitening.

Grey stains, dental trauma and discolouration beneath the tooth surface may require alternative treatment. Crowns, veneers and fillings won’t whiten like natural teeth.

If you have sensitive teeth or any such existing dental concerns, check whether teeth whitening is safe for your teeth before treatment.

Your dentist can suggest the most suitable teeth whitening procedure after assessing your oral health.

How Much Does a Teeth Whitening Procedure Cost in London?

The teeth whitening procedure cost in London depends on the treatment system, your dental needs and the care included.

Treatment at Aldgate Dental Care Price
Boutique Whitening From £355
Enlighten Whitening From £695
Consultation £30, deducted from treatment cost if you proceed, subject to current terms

For a detailed breakdown of teeth whitening costs in the UK, including factors that affect pricing, see our cost article.

When comparing teeth whitening in London, check what the price includes, who performs the treatment and what aftercare is provided. Your dentist can explain suitable options and any additional costs before you begin.

Frequently Asked Questions About the Teeth Whitening Procedure

Here are answers to common questions about whitening treatment, results, safety and aftercare.

Q1. How Long Does a Dentist Teeth Whitening Procedure Take?

In-clinic teeth whitening usually takes around one to two hours, depending on the system used. Dentist-prescribed home whitening may take several days or weeks to achieve the desired results.

Q2. Is the Teeth Whitening Procedure Painful?

Professional teeth whitening is generally well tolerated, although temporary sensitivity or mild gum irritation can occur. Tell your dentist about existing sensitivity before treatment so they can recommend suitable precautions.

Q3. How Many Shades Whiter Can Teeth Become?

Results depend on your natural tooth colour, the cause of discolouration and the whitening system used. Your dentist can discuss realistic expectations, although a specific shade change cannot be guaranteed.

Q4. Can I Eat Normally After Teeth Whitening?

You can usually eat normally, but your dentist may recommend limiting strongly coloured foods and drinks for a short period. Avoid anything that triggers sensitivity and follow your aftercare instructions.

Q5. How Long Do Teeth Whitening Results Last?

Results may vary depending on your diet, oral hygiene and treatment type. Following your dentist’s maintenance advice can help preserve your brighter smile and reduce future staining.

Book Your Teeth Whitening Consultation in London

If stained or discoloured teeth are affecting how you feel about your smile, professional whitening may be a choice worth considering and discussing with your dentist.

At Aldgate Dental Care, we can assess your teeth, explain the available whitening treatments and help you understand which approach may suit your needs. You can discuss your desired shade, expected treatment timeline, possible sensitivity and costs before making a decision.

Book a consultation with our team to discuss teeth whitening in London and find out whether professional whitening is suitable for you.