Aesthetic dentistry

Teeth whitening at SMILE meets DESIGN

Teeth whitening in Cologne

Would you like lighter teeth? We discuss the shade you have in mind and assess what is possible for your teeth.

On Doctolib, first select your insurance type, then confirm “Beratung Bleaching” (whitening consultation). Call to arrange a whitening appointment ↗

Side view of a smile in close-up
Close-up of a smile, not a whitening treatment result.

At a glance

What to know before whitening

What can become lighter?
Whitening changes coloured compounds in natural teeth. Fillings, crowns and veneers do not lighten in the same way.
What does planning include?
Examining your teeth and gums, checking existing restorations and discussing the shade you would like.
What can be predicted?
The degree of whitening and how long it remains visible vary. A particular shade cannot be promised.

Your starting point

What kind of discolouration is it?

Surface, tooth tissue or an existing restoration: choose a question to understand the difference.

Surface stains: could a professional cleaning be enough?
AI-generated Upper front teeth with fine external staining near the gumline; AI-generated educational illustration.
Shown: fine external staining on the upper front teeth. Educational illustration · not a patient case

ON THE TOOTH

Surface staining differs from natural tooth colour.

Coffee, tea and tobacco can contribute to surface staining. A professional cleaning may remove these deposits. The natural colour of the tooth remains.

If you would also like a lighter natural shade, we assess whether whitening could be suitable.

WHAT WE DISCUSS AT YOUR VISIT

What can cleaning change, and what colour belongs to the tooth itself?

Understand professional cleaning
Natural tooth colour: what does whitening change?
AI-generated A front tooth in a simplified cutaway showing light enamel, yellowish dentine and reddish inner pulp tissue; AI-generated educational illustration.
Shown: a front tooth in a simplified cutaway.
  • Enamel
  • Dentine
  • Pulp
Educational illustration · not a patient case · simplified cutaway

WITHIN THE TOOTH

Natural tooth colour has several layers.

Enamel and the dentine beneath it both contribute to the colour you see. Changes over a lifetime also play a part.

Whitening gels can chemically change coloured compounds in natural tooth tissue. How noticeable the change is depends partly on the cause of the discolouration.

WHAT WE DISCUSS AT YOUR VISIT

What is your starting shade, and what change could realistically be achievable?

Understand natural tooth colour
One darker tooth: why examine it separately?
AI-generated Upper front teeth with a darker central incisor on the right of the image; AI-generated educational illustration.
Shown: the central incisor on the right appears darker. Educational illustration · not a patient case

A SEPARATE ASSESSMENT

One tooth stands out.
We take a closer look.

A single darker tooth may have a different cause from an overall darker tooth colour. A previous injury, root canal treatment or other changes may play a part.

We therefore examine that tooth specifically. Some root-filled teeth can be whitened from inside, which requires a separate treatment decision.

WHAT WE DISCUSS AT YOUR VISIT

When did the difference appear, what treatment has the tooth had, and what does the examination show?

When one tooth becomes darker
Fillings and crowns: what keeps its colour?
AI-generated Upper front teeth with a lighter ceramic crown on the central incisor on the right of the image; AI-generated educational illustration.
Shown: a lighter ceramic crown on the central incisor on the right. Educational illustration · not a patient case

CONSIDERING THE MATERIALS

Different materials
respond differently.

An existing filling or crown does not whiten in the same way as natural tooth tissue. If the neighbouring teeth change shade, the restoration may become more noticeable.

That does not automatically mean it needs to be replaced. Its position, condition and the appearance you would like all matter.

WHAT WE DISCUSS AT YOUR VISIT

Which surfaces are natural tooth tissue, and how could the overall appearance change?

Plan around fillings & crowns
In brief: natural tooth and crown

Natural tooth: Whitening can lighten its colour. The degree of visible change depends partly on the starting shade and the cause of the discolouration.

Crown, veneer or filling: Existing restorations do not whiten in the same way as natural tooth structure. They therefore need to be considered when planning the colour. A shade difference does not automatically mean that a sound restoration needs replacing.

Read the image description

The teaching image shows the upper front teeth and pink gums. The central incisor on the right side of the image is shown lighter and smoother than the neighbouring teeth. In this teaching example, it represents an artificial crown.

A tooth’s appearance alone cannot reliably identify its material. This is not a real patient or a treatment result.

AI-generated educational illustrations, not patient cases or a diagnosis. Your selection does not predict which treatment is suitable for you.

Treatment at our practice

What happens during whitening at SMD?

Reception at the SMILE meets DESIGN practice in Cologne

Our practice in central Cologne.

At SMD, we use fläsh with whitening gel and a whitening lamp. First, we examine your teeth and gums and discuss your preferred shade.

  1. 01

    Understand your starting point

    We assess your teeth, gums and existing fillings or ceramic restorations. We record your starting shade. You tell us what change you would like and whether your teeth are already sensitive.

  2. 02

    Agree on preparation and treatment

    Deposits that could interfere with whitening are removed beforehand. The examination shows whether you need professional cleaning or other preliminary treatment. We explain the planned steps and appointments.

  3. 03

    Whiten under supervision

    For fläsh whitening, we protect the gums and use the gel together with the whitening lamp. The number and length of applications depend on the product and your clinical situation. Let us know immediately if you feel discomfort.

  4. 04

    Discuss the result and aftercare

    We check your teeth and gums, record the shade and explain aftercare. Any further review or later top-up is discussed individually.

How much time should I allow?

As a guide, the fläsh manufacturer describes approximately one hour of treatment. The examination and any preparation may require extra time or a separate appointment. We confirm the time planned for your visit beforehand.

Comparing the options

Professional cleaning, whitening at the practice and home products

The terms can sound similar. What matters is where a treatment acts and how it is supervised.

Professional teeth cleaning

What changes
Plaque, deposits and accessible surface stains are removed.
What it involves
Cleaning tailored to your needs and personal oral-care advice.
Important limit
It does not bleach the tooth’s natural base colour.

At SMILE meets DESIGN

In-practice whitening

What changes
Whitening gel changes coloured compounds in natural tooth tissue.
What it involves
Examination, planning, gum protection and controlled application.
Important limit
Results and sensitivity vary. Fillings and crowns do not whiten; a colour difference may become visible.

Dentist-supervised home whitening

What changes
Whitening with a system intended for use at home.
What it involves
A dental examination, an appropriate system, instructions and reviews.
Important limit
This is not the same as an over-the-counter kit.

Over-the-counter products

What changes
Varies by product and ingredient; some mainly remove surface stains.
What it involves
Use depends on the product. It does not establish the cause of discolouration.
Important limit
The word “whitening” alone tells you little about effectiveness or individual suitability.

This comparison explains different approaches. The treatment described for our practice is fläsh whitening; inclusion here does not mean that every method is offered at SMD.

What happens inside the tooth

How does whitening gel work?

Whitening gels often contain hydrogen peroxide or carbamide peroxide. Reactive components change coloured molecules within the tooth. No tooth tissue is ground away for this. Whitening is intended to change tooth colour, not tooth shape or position. Fillings, crowns and veneers do not whiten in the same way as natural teeth.

Whitening in our dental glossary ↗

Before deciding

Who is whitening suitable for, and what are its limits?

Your dental health and the shade you would like are considered together.

Five questions before whitening ↗

What we check beforehand

Tooth decay, leaking fillings, concerns around crown margins or gum problems may need treatment first. Exposed tooth necks and existing sensitivity also need to be considered. A product must not be used if you have a known allergy to one of its ingredients.

Cosmetic teeth whitening is a treatment for adults. It is not recommended during pregnancy or breastfeeding. If just one tooth looks different, we first investigate why.

Results have limits

Natural teeth do not need to be brilliant white. We cannot guarantee a particular shade or number of shade changes. Fillings, crowns and veneers do not whiten in the same way. Tooth shape and position remain unchanged too.

Sensitivity can occur

Teeth may become more sensitive during or after whitening, and the gums can become irritated. If there is severe pain, we stop the application immediately and assess the cause. Contact the practice if symptoms persist or worsen.

Planning the cost

What determines the cost?

The cost of whitening depends on the planned treatment. Purely cosmetic whitening is a privately paid elective service. The services and fees are agreed in a written treatment and cost plan before treatment begins. Reimbursement is not guaranteed.

01

Examination & planningYour starting point, desired shade and existing restorations.

02

Any necessary preparationFor example, any professional cleaning or preliminary treatment needed.

03

The whitening treatmentThe approach planned for your clinical situation.

04

Possible further stepsFor example, a later top-up or separate shade planning for existing restorations.

This overview explains possible elements of treatment, rather than a fixed package. Not everyone needs every step. A colour difference does not automatically require sound restorations to be replaced.

After treatment

Eating, drinking and care after whitening

Explore these three stages. Always follow the individual advice given for your treatment.

4h

Choose water to drink.

The fläsh patient information recommends drinking water for the first four hours and avoiding staining influences such as coffee, tea, red wine and tobacco. Follow the instructions discussed with you.

Read the fläsh patient information (German) ↗

Care for sensitive teeth

Continue your oral care. If you have sensitivity, we can discuss suitable care. Do not add other whitening products without advice. Call us if discomfort persists or worsens.

Call the practice · 0221 669 401 80 ↗

Tooth colour can change again.

How long whitening remains visible depends partly on your starting point, oral care, smoking and diet. The German Dental Association describes a possible effect lasting several months to around two years. This is a guide, not a guarantee. Any top-up is planned after a fresh assessment.

German Dental Association guidance (German) ↗

Dental knowledge on film

Tooth colour explained on film.

A short German-language film about tooth colour, whitening and its limits. An English transcript is available below.

Illustration: Understanding teeth whitening AI-generated

Clearly explained · German film 1:53 min

Understanding teeth whitening.

What whitening changes, and why examination, protection and realistic expectations matter.

No sound · German text on screen

Press play whenever you are ready.

Simplified educational illustrations. Suitability, treatment and aftercare are discussed individually after a dental examination. An English translation of the complete film text is provided below.

English transcript and sources

Understanding teeth whitening.

Possibilities and limits.

Not all discolouration is the same.

Natural tooth colour comes from the interaction of enamel and dentine. Surface deposits can also stain teeth. Cleaning removes these deposits; whitening acts on coloured compounds within the tooth.

Changing coloured compounds chemically.

Whitening gels usually contain peroxides. These can enter the hard tooth tissues and change coloured molecules through oxidation. How noticeable the whitening is depends partly on the type of discolouration.

The examination comes first.

Before whitening, the examination includes checking for decay, leaking restorations and gum problems. Some findings may require preliminary treatment. Sensitive teeth and individual circumstances are taken into account when planning.

Supervised and individual.

Whitening can take place in the practice or at home using trays under a dentist’s guidance. Gum protection, gel quantity and application time depend on the method. Extending applications yourself can increase the risk of irritation.

Fillings do not whiten.

Whitening changes the colour of natural tooth tissue. Fillings, crowns and veneers do not whiten with it. This can make differences in shade noticeable. Whether anything might need adjusting later is part of the initial discussion.

Results remain individual.

Temporary sensitivity and gum irritation can occur. If there is severe pain, the application is stopped and dental advice sought. The shade and duration of whitening vary from person to person; a specific brightness cannot be promised.

Get advice for your teeth.

Suitable treatment options can only be assessed after a dental examination and a personal discussion.

Common questions

Questions about whitening

From cost and appointment length to sensitivity and how long whitening lasts: answers to common questions.

These answers explain general principles. We assess your individual suitability at the examination.

How much does professional whitening cost?

The cost depends on the examination, necessary preparation and extent of whitening. Purely cosmetic whitening is an elective service paid for privately. Services and fees are agreed in a written treatment and cost plan before treatment; reimbursement is not guaranteed.

Read about cost planning ↗
Can whitening harm teeth or gums?

Whitening is not risk-free. Temporary tooth sensitivity and gum irritation can occur. Decay, leaking fillings and other concerns need to be examined beforehand. We assess these conditions and plan treatment accordingly. If severe pain occurs, treatment is stopped and the cause is investigated.

Read about suitability and limits ↗
What is the difference between cleaning and whitening?

Cleaning removes deposits and surface staining. Whitening acts on coloured compounds in natural tooth tissue. Cleaning can therefore remove visible deposits without lightening the natural base colour. At your examination, we can discuss which of these contributes to the colour you see.

Is fläsh whitening the same as laser whitening?

For fläsh whitening, we use a whitening lamp together with the gel. A lamp is not automatically a laser. Planning depends on the system, its application and your dental situation; the name of a light source alone does not predict treatment success.

How long is a whitening appointment at your practice?

The time needed depends on the examination, preparation and planned application. Before treatment, we explain which steps take place at each appointment and how much time to allow. A manufacturer’s application time is not necessarily the duration of your full visit.

Do I always need professional cleaning before whitening?

Deposits and surface stains that could interfere should be removed before whitening. The examination establishes whether you need professional cleaning, when it should take place and what it should involve. A fixed appointment rule does not suit every situation.

Will my fillings, crowns or veneers become lighter too?

Existing restorations do not whiten in the same way as natural teeth. Differences in shade may therefore become more noticeable. We take visible restorations into account before treatment. A possible colour difference does not automatically mean that sound fillings or crowns need replacing.

Can an individual dark tooth be whitened?

Individual teeth can be assessed separately and whitened in certain circumstances. The cause, condition and previous treatment matter. Internal whitening methods exist for some root-filled teeth. We can discuss suitable options for an individual tooth after examining it.

Does teeth whitening hurt?

Temporary sensitivity can occur during or after application. Your gums may also react. Tell us immediately if you feel discomfort during treatment. Severe pain is not accepted as a necessary part of whitening: the application is stopped and assessed.

How white can my teeth become?

This depends on your natural tooth colour and the type of discolouration. Not every tooth responds in the same way. We record the starting point and discuss a realistic shade goal. Other people’s photographs or a digital simulation cannot reliably predict your personal result.

How long will the result remain visible?

The colour can gradually change again. How quickly this happens depends partly on oral care, smoking, diet and the starting situation. Whitening is therefore not a permanent shade guarantee. Any later top-up is planned according to the current condition of your teeth, rather than a fixed calendar.

When can I drink coffee again?

For the fläsh system we use, the patient information recommends water as your drink and avoiding staining influences for four hours. Follow the personal aftercare instructions from the practice. Any other treatment you have had may also affect the advice.

Is a home whitening kit comparable to treatment by a dentist?

Dentist-supervised home whitening is a specific treatment approach with a prior examination, an appropriate system and instructions. Over-the-counter products differ in their active ingredients, concentrations and application. “For home use” does not by itself explain how a product works or whether it suits your teeth.

Do charcoal, lemon juice or other home remedies help?

For many home remedies, there is no reliable evidence of safe tooth whitening. Acidic or highly abrasive applications can be problematic. Discuss the effect you want before trying them yourself. Often, the first useful step is to distinguish surface staining from the natural tooth colour.

Home remedies for whitening: a fact check

Dr Niusha Barahmand Pour at her dental practice in Cologne

Meet us in Cologne

What do we discuss at your whitening consultation?

Dr Niusha Barahmand Pour and the SMILE meets DESIGN team offer consultations in central Cologne. We discuss your preferred shade, any existing fillings or crowns, and possible tooth sensitivity. During the examination, we assess whether whitening may be suitable and what preparation would be appropriate.

Book a whitening consultation

On Doctolib, first select your insurance type, then confirm “Beratung Bleaching” (whitening consultation). Call to arrange a whitening appointment ↗

Kreishaus Galerie
Sankt-Apern-Straße 17–21 · 50667 Cologne
0221 669 401 80
Contact & directions ↗ · Meet Dr Barahmand Pour ↗
Sources, context & image information

Editorial source check: 4 November 2026. Additional source check on 5 November 2026: risks, cost planning and the manufacturer’s treatment-time guidance. This information does not replace an individual examination. The interactive illustrations explain principles; they do not calculate an individual treatment result. Tooth-shade illustrations are educational images, not patient cases or evidence of results; the existing explainer film also contains AI-generated illustrations. Practice and dentist photographs show SMILE meets DESIGN.