10 things you need to know about teeth whitening: myths and facts

Teeth whitening is a cosmetic dental treatment that lightens the colour of the teeth and reduces stains. When carried out correctly, on the advice of a dentist, it does not damage the enamel. Results vary depending on the method used and the cause of the discolouration, and are not permanent.

Below, Dr Oana Tima-Lazăr, a cosmetic dentist, explains what teeth whitening involves, what it can and cannot do, the main methods available, and how you can distinguish between common myths and accurate information. 

Teeth whitening is a cosmetic dental procedure that lightens the colour of natural teeth by reducing stains and pigments, without altering their shape. The procedure does not change the colour of fillings, crowns or dental veneers.

Furthermore, whitening cannot alter the shape or position of the teeth, nor can it correct structural defects in the enamel.

In most cases, the treatment uses gels based on hydrogen peroxide or carbamide peroxide. The active substances penetrate the enamel and dentine and oxidise the molecules responsible for tooth discolouration, thereby reducing the intensity of the pigments.

“A dental assessment is required before treatment. The dentist can determine whether whitening is appropriate and whether any existing restorations in the visible area might affect the final aesthetic result.” – Dr Oana Tima. 

There are several methods for improving the colour of teeth. These differ in terms of the substances used, their concentration, the duration of treatment, their effectiveness and the level of medical supervision.

Choosing the right method depends on the cause of the discolouration, the condition of the teeth and gums, and the desired result.

Professional in-clinic teeth whitening

Professional whitening is carried out in the dental surgery under the supervision of a dentist. Whitening gels are used, and before application, the soft tissues are protected to reduce the risk of irritation.

In some systems, a light source may also be used, but the whitening effect is primarily determined by the chemical agent.

The advantages of in-clinic treatment include:

• visible results within a short time;
• treatment carried out under the supervision of a dentist;  
• concentrations tailored to each individual case;  
• the ability to manage tooth sensitivity, should it occur.

It may be recommended for patients who wish to see results more quickly and who are suitable candidates for the treatment.

At-home teeth whitening, recommended by a dentist

At-home whitening recommended by a dentist usually involves the use of custom-made trays and a whitening gel whose concentration is selected according to the clinical situation.

The trays are custom-made and allow for even distribution of the gel, whilst limiting its contact with the gums.

“The dentist determines how long the trays should be worn, the amount of gel to use and the total duration of the treatment. Depending on the product, the trays may be worn for a specific period each day or according to an individualised protocol. Following the instructions is essential both for the result and for reducing the risk of tooth sensitivity.” – Dr Oana Tima

Over-the-counter whitening products

There are numerous products available without an individualised dental protocol:

• Whitening toothpaste mainly acts on superficial stains, using abrasive and polishing agents. Its effect on the internal colour of the tooth is limited.
• Whitening strips may contain peroxide in lower concentrations and may be effective for certain mild or moderate discolorations. However, the result depends on the type of stains and correct use.
• Whitening kits may include universal mouth trays, gels or various devices designed to activate the product. Poorly fitting mouth trays can cause the gel to come into contact with the gums and lead to tissue irritation.

Whitening products are not suitable for every patient. They should not be used if there are:

• untreated tooth decay;
• periodontal disease;
• severe tooth sensitivity;
• extensive restorations in the visible area.  

Furthermore, excessive use may increase the risk of tooth sensitivity and gum irritation. 

There is a great deal of conflicting information circulating about teeth whitening, stemming from personal experiences, adverts or information shared online. Distinguishing fact from fiction helps patients choose the right treatment and avoid using products incorrectly.

Myth 1: Teeth whitening is harmful

Fact: When carried out correctly, using products designed for this purpose and in accordance with medical guidelines, teeth whitening is considered a safe procedure for patients for whom the treatment is indicated.

The most common side effects are:

• temporary tooth sensitivity;  
• gum irritation, particularly when the gel comes into contact with soft tissues.

The risks may increase when products are used excessively, in inappropriate concentrations or without a prior assessment of oral health.

Myth 2: All whitening products work in the same way

Reality: products differ considerably. The concentration of the active ingredient, the type of whitening agent, the duration of contact with the teeth and the method of application all influence the effectiveness of the treatment.

A product designed to remove superficial stains cannot have the same effect as a treatment designed to alter pigmentation within the tooth structure.

For this reason, the results of commercially available products cannot be directly compared with those of treatments recommended and monitored by a dentist.

Myth 3: Whitening works on veneers, crowns and fillings

Reality: Teeth whitening works on natural dental tissue.  

Ceramic veneers, crowns, fillings and other restorations do not change colour as a result of the whitening treatment.

“This is one of the reasons why existing restorations must be assessed before treatment. After whitening, in certain situations there may be a colour difference between the natural teeth and visible restorations, and the dentist will determine whether further interventions are needed to harmonise the result.” – Dr Oana Tima 

Myth 4: The results of whitening are permanent

Reality: Teeth whitening does not provide a permanent result. Over time, teeth may gradually become discoloured again. The rate at which this happens varies from patient to patient and is influenced by diet, oral hygiene, smoking, the initial colour of the teeth and the whitening method used.

Factors that can contribute to discolouration include:

• frequent consumption of coffee, tea, red wine and other pigmented drinks;
• smoking or the use of other tobacco products;  
• poor oral hygiene;
• the frequency of professional dental cleanings;  
• the type of initial colour and the whitening method used.

Where appropriate, the dentist may also recommend maintenance treatments, although there is no universally applicable frequency for all patients.

Myth 5: Teeth whitening solves every aesthetic problem

Reality: Whitening mainly changes the colour of natural teeth.

It cannot change the shape of a tooth, its position or certain structural defects.

When the cosmetic issue is not caused solely by colour, the dentist may recommend other dental treatments:

• ceramic veneers;
• direct restorations using composite materials;
• dental crowns;
• orthodontic treatment;
• minimally invasive aesthetic reshaping.

The right treatment therefore begins with identifying the cause of the aesthetic concern. 

Teeth whitening is a cosmetic dental procedure that can improve the colour of your natural teeth, but it must be carried out following a dental assessment.

It is important to bear in mind a few key points:

• Whitening has specific indications and is not the right solution for all types of discolouration.
• Results vary from patient to patient. The initial colour, thickness and characteristics of the enamel, the cause of the discolouration and oral health can all influence the response to treatment.
• Furthermore, there is no single final shade that can be guaranteed for all patients. The aim is to achieve a harmonious aesthetic improvement tailored to the individual’s situation.
• Healthy teeth and gums contribute both to the safety of the treatment and to achieving a predictable result.

That is why a dental consultation is the first step before choosing a whitening method. 

The consultation enables the cause of the discolouration to be identified and the health of the oral cavity to be assessed.

The dentist assesses the teeth and gums, identifies any cavities, checks for gum inflammation and assesses the degree of tooth sensitivity.

Active cavities must be treated before whitening. At the same time, gingivitis or active periodontal disease requires treatment before whitening products are applied.

Another important aspect is the assessment of existing restorations: crowns, veneers, bridges or fillings. As these do not change colour during whitening, their position and colour must be taken into account before determining the desired outcome.

Depending on the clinical examination and the patient’s objectives, the dentist may recommend:

• in-clinic professional whitening;
• home whitening using custom-made trays;
• a combination of the two options;
• another cosmetic dentistry solution where whitening is not recommended. 

The success of the treatment does not depend solely on the product used. Teeth must be assessed for cavities, cracks, damage or other problems that may affect the safety and comfort of the treatment.

The gums must also be healthy. Inflamed tissues are more prone to irritation if they come into accidental contact with the whitening gels.

In many cases, a professional dental clean may be recommended prior to treatment. Removing bacterial plaque and tartar helps both to assess the true colour of the teeth and to ensure uniform contact between the product and the tooth surface.

Cavities must be treated before whitening, and any existing tooth sensitivity must be assessed.

For patients with tooth sensitivity, the dentist may recommend desensitising products, remineralising gels, adjusting the application time, or using different concentrations of the whitening agent. 

The choice of the appropriate method should be based on the cause of the discolouration, the state of oral health, the degree of sensitivity and the desired outcome.

Below, the main options can be compared in terms of their advantages and limitations. 

Both in-clinic teeth whitening and at-home treatment carried out in accordance with the dentist’s advice may be appropriate.

The main differences relate to the speed of results, the treatment protocol, cost and the level of supervision.

Whitening toothpastes are among the most affordable products designed to improve the appearance of teeth, but their effects need to be properly understood.

1. They mainly act on superficial stains on the enamel.
2. Most cannot significantly alter the internal colour of the tooth, which is why they are not the equivalent of a professional whitening treatment.
3. Some products may have a more pronounced abrasive effect. Excessive use of highly abrasive products may not be suitable for certain people.
4. To use them correctly, it is recommended that you choose suitable products and maintain a comprehensive oral hygiene routine.

Not all hair colours respond in the same way to bleaching treatments. When choosing a method, the following should be taken into account:

• the cause of the discolouration;
• the original colour of the teeth;
• tooth sensitivity;
• the presence of crowns, veneers or fillings in the visible area;
• the health of the teeth and gums;
• the desired aesthetic result;
• the available budget.

“A patient with superficial stains may require a different approach to a patient with intrinsic discolouration. Similarly, the presence of restorations in the anterior region may influence the sequence of treatment stages. A consultation allows us to choose a solution tailored to the actual situation, rather than applying a one-size-fits-all approach.” – Dr Oana Tima 

Price is an important criterion, but it should not be the only factor taken into account.

A whitening method must also be assessed in terms of its effectiveness – that is, its ability to tackle the specific type of discolouration – and its safety for teeth and gums.

Oral health is just as important as the product chosen. Treating tooth decay, managing gum inflammation and identifying any sensitivity before whitening help to reduce the risk of unwanted side effects.

Therefore, before choosing a treatment, a dental consultation is recommended, during which the appropriate method, the expected outcome and the associated costs can be discussed.

For up-to-date information on the costs of treatments available at DENT ESTET clinics, you can also consult the price list or book an appointment for a personalised assessment.

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5. Epple M, Meyer F, Enax J. – A critical review of modern concepts for teeth whitening, Dentistry Journal, 2019