Teeth whitening gels used by dentists

The natural color of teeth is typically within a range of whitish-yellow-grayish shades, though they darken naturally with age. 

Their appearance can also be affected by other factors, like the accumulation of stains acquired from consuming certain foods and drinks, using tobacco products, excess fluoride, or using certain antibiotics, like tetracycline. 

There are a number of teeth whitening options that can effectively lighten the existing shade of your teeth without removing any of the tooth enamel.

teeth whitening gels used by dentists

Teeth whitening options for sensitive teeth

Although natural teeth are not completely white, many people want a brighter smile. Even if you have sensitive teeth, you can safely combat discoloration as long as you visit your dentist before beginning any whitening treatments. The solutions that are best for you will depend on your dental health. 

To address stained or discolored teeth, a wide range of teeth whitening options have become available, and can be divided into two broad categories: bleaches and surface whiteners.

Teeth whitening toothpaste that works​

Teeth whitening toothpaste falls in the category of surface whiteners, which utilize special abrasives to remove surface stains. These abrasive elements are usually only finer versions of those found in regular toothpastes, so they don’t cause excessive wear of tooth enamel.

Does teeth whitening toothpaste work?

The effectiveness of teeth whitening toothpaste depends on the extent of tooth staining or discoloration, and should not be used as an alternative for professional cleaning. There are also some chewing gums that have a similar whitening effect on your teeth.

Teeth whitening bleach gel

Most of the products in this category are peroxide-based (carbamide- or hydrogen-peroxide) and are known to change the natural color of the tooth. However, not all stains respond to these treatments. So, people considering using tooth-bleaching gels should consult with a dentist to establish the cause of the discoloration, and identify whether they are proper candidates for bleaching. This step is particularly important for individuals with root canal treatments, fillings, crowns, or very dark stains.

If you are a suitable candidate for bleaching, your dentist will use one of two methods:

  • Vital bleaching – performed on natural teeth that have become discolored with age, or due to food, drinks, or tobacco
  • Non-vital bleaching – performed on dead teeth, like those that have stained due to root canal

Teeth whitening bleach trays

Custom teeth whitening trays are worn over the teeth with whitening gel to deal with the discoloration. Tray whitening procedures are carried out at home, some at the dentist’s office, while others do both. But before any of them can begin, your dentist must design and fabricate your custom-fitted trays.

The procedure for using custom teeth whitening trays to achieve a whiter smile is rather simple.

  • To generate the molds needed to make your whitening trays, your dentist will take impressions of your teeth.
  • A bleaching solution is put inside the trays after you’ve received them, and you wear them for up to 4 hours per day for 1–2 weeks.
  • Within that time, you’ll see a noticeable improvement in the color of your teeth.

Over-the-counter vs. Custom Teeth Whitening Trays

Applications of over-the-counter whitening trays are inferior to those of custom trays for two key reasons.

  • Fit and Comfort: Custom trays are designed to fit snugly but comfortably, which makes them more effective than over-the-counter trays that tend to run large and loose.
  • Gum irritation can happen when a tray doesn’t fit snugly over your teeth and gel leaks out, causing pain and discomfort to the gums.

Types of teeth whitening gels commonly used by dentists

1. Carbamide Peroxide Gels:

Carbamide peroxide is a key ingredient in many teeth whitening gels. When applied, it breaks down into hydrogen peroxide and urea, which effectively oxidize and remove stains from the enamel. The percentage of carbamide peroxide in these gels can range from 6% to 35%, with higher concentrations delivering more potent whitening effects.

a. 16% CP Teeth Whitening Gels:

Notable for producing noticeable results in a relatively short time, 16% CP teeth whitening gel is applied using custom-fitted trays worn for a few hours daily. Users typically experience less sensitivity compared to other whitening agents like hydrogen peroxide. However, prolonged or frequent usage of 16% CP gel may cause discomfort in some individuals. Proper adherence to instructions and consultation with a dental professional are essential.

b. 35% CP Teeth Whitening Gels:

The popularity of 35% CP teeth whitening gel stems from its potent and fast-acting results. This professional-grade gel contains a high quantity of carbamide peroxide, efficiently eliminating tough spots and discoloration from teeth. The quickness of the 35% CP gel enables noticeable improvements in teeth brightness after just one procedure, making it a practical choice for busy individuals. Its effectiveness surpasses over-the-counter whitening products, providing exceptional results even against challenging stains caused by beverages like coffee, tea, and tobacco.

c. 44% CP Teeth Whitening Gels:

Dental professionals carefully select and educate patients on the proper use of 44% CP teeth whitening gel to avoid potential side effects like tooth sensitivity or gum irritation. Its powerful bleaching properties require meticulous supervision, especially for patients with pre-existing dental issues.


A higher concentration, however, may increase the risk of gum irritation and tooth sensitivity after whitening. It is advisable to start with a lower concentration and gradually increase as needed under the guidance of a dental professional.

2. Hydrogen Peroxide Gels:

Hydrogen peroxide-based whitening gels are another popular choice for achieving a brighter smile. The most common concentration used is 35%. While some individuals may opt for lower concentrations like 6% or 8%, higher concentrations (16% or greater) are generally discouraged due to the potential risk of tooth and gum damage.

a. 10% HP Teeth Whitening Gels:

With a safe and effective 10% hydrogen peroxide (HP) formula, this gel gently whitens teeth without causing discomfort or damage. Consistent use leads to teeth that are several shades whiter, effectively breaking down stains and leaving teeth looking clean and bright. Dentists can customize treatment plans based on individual needs, and the gel’s convenient syringe makes precise application a breeze.

b. 16% HP Teeth Whitening Gels:

Ideal for lightening dental enamel’s natural shade, 16% HP teeth whitening gel can be applied directly to the teeth or used with custom-made trays for more even gel dispersal. For optimal results, patients are recommended to use the gel for 30 minutes to an hour daily for one to two weeks. It is crucial to avoid overuse, as excessive application may lead to tooth sensitivity and irritation.

c. 35% HP Teeth Whitening Gels:

While 35% HP teeth whitening gel offers highly effective results, it should only be used under the supervision of a dental professional due to its strong concentration. Improper usage may lead to tooth sensitivity, gum irritation, or chemical burns. 

The advantage of 35% HP teeth whitening gel lies in its ability to produce dramatic results in a short period, effectively removing even stubborn stains. However, results may vary depending on individual factors such as age, diet, and oral hygiene habits


Hydrogen peroxide gels can be applied directly to the teeth or used in custom-made trays for a more even distribution. The treatment duration may vary based on the severity of stains, and it is essential to follow instructions to prevent sensitivity.

3. PAP Whitening Gels:

PAP (Phthalimido peroxy caproic acid) whitening gels feature a relatively new whitening agent effective in removing dental stains. Concentrations typically range from 2% to 18%, with 12% being a common choice. Proper usage under professional guidance is crucial to avoid potential sensitivity or damage.

Choosing the Right Gel

Selecting the appropriate teeth whitening gel is vital to achieving the desired results safely and effectively. Dental professionals can tailor treatments based on individual needs, ensuring the best outcomes.

  • Duration of Treatment and Results:

The time it takes to see teeth whitening results varies depending on the gel’s concentration and the level of discoloration. Some gels, like in-office treatments with higher concentrations, may offer immediate results, while others may require several weeks of consistent use.

  • Longevity of Whitening Effects:

While teeth whitening can provide noticeable results, it is not a permanent solution. Results can last for several months to years, depending on individual habits and lifestyle choices. Maintaining good oral hygiene and avoiding stain-causing substances can help prolong the effects.

  • Professional Supervision is Key:

Teeth whitening is most effective and safe when performed under the supervision of a dental professional. Dentists can assess oral health, recommend the right gel and application method, and address any concerns or sensitivities. Whether you choose in-office treatments or at-home kits, professional guidance ensures a confident and radiant smile.

Teeth whitening bleach on gums

The idea of brushing with abrasive chemical agents or using high-concentration peroxide gels surely sounds unpleasant if you already have sensitive teeth, which means you have exposed dentin. 

The American Dental Association cites gum inflammation and tooth sensitivity as potential adverse reactions from peroxide-based whitening treatments. 

Fortunately, the effect can be minimized by getting professional teeth whitening at the dentist’s office, or wearing custom bleaching trays that reduce the risk of bleach gel leaking out and irritating the gums. 

Moreover, in the vast majority of cases, gum and tooth sensitivity is a temporary side-effect that should vanish in 1-3 days following treatment.

What to expect during a dental appointment for whitening

When considering teeth whitening, it is important that you get proper assessment to rule out any possible permanent risks or serious side effects with a specific treatment. During the assessment, your dentist will:

  • Diagnose the cause of any stains or discoloration
  • Ensure your mouth is healthy before recommending a whitening option
  • Discuss with you the options available and the best one for your case
  • Advise you on factors that may influence the whitening process, like antibiotic staining
  • Evaluate whether your crowns, fillings, and veneers need replacement, because they don’t stain or discolor
  • Check for gum recession
  • Discuss possible tooth sensitivity and how to address it

How many teeth whitening sessions do i need?

Most patients need just one teeth-whitening treatment session in the dentist’s office, though it may require multiple administrations of the bleaching solution to gradually change the shade of your teeth to the desired one. If you’re wearing the at-home whitening trays, then the process may take up to two weeks to achieve the desired result.

What to eat after teeth whitening

Your dietary and beverage choices over the following 48 hours should be carefully selected because of not only the potential gum sensitivity after bleaching, but also the high risk of tooth damage due to a temporary dentin exposure. The foods and drinks we consume can have a substantial impact on the overall color of our teeth, as several studies and observations demonstrate.

However, your teeth are considerably more susceptible to discoloration if you recently had them whitened. A white diet is therefore advised for anyone who has recently undergone the procedure. Recommended food options include light-colored, acid free items such as:

  • Chicken/Turkey
  • White fish
  • Rice – as an accompaniment for the meats
  • Pasta – but avoid colored sauces like tomato sauce or green pesto
  • White Cheese – without the wine
  • White Onion – avoid red onion
  • Egg Whites – avoid the yoke
  • White Potatoes – without the skin
  • White Bread – without the crust
  • Bananas
  • White Yoghurt
  • Sugarless porridge

You should also avoid the following during the first 48 hours of bleaching, and limit their consumption in future since they have a staining effect on your teeth.

  • Black Coffee – add milk if you must drink
  • Black Tea – add milk if you must drink
  • Red Wine – the acidity and dark colors make it a high-risk drink
  • White wine – its acidity weakens tooth enamel, making you more vulnerable to other staining food
  • Fizzy Drinks – they contain acid and color
  • Fruit Juices – have high acidity
  • Dark condiments – soy sauce, balsamic vinegar, even tomato sauce have both color and acidity
  • Dark Fruits
  • Curry
  • Sweets and Chocolate
  • Tobacco products

How do I proceed with teeth whitening?

Considering that there are numerous teeth whitening options, including in-office and at-home bleaching options, we suggest that you talk to professional and experienced dentists before selecting a method.



  • Editorial team

    A team comprising oral health care professionals, researchers, and professional Writers, striving to impart you with the knowledge to improve your oral health, and that of your loved ones. 

  • Lilly

    Lilly, aka, Liza Lee, is a passionate community oral health officer and our lead writer. She's not only well-versed in performing a multitude of dental procedures, including preventive, restorative, and cosmetic, but also an avid writer. Driven by the significant oral health burden all around her, Lilly strives to build capacity and promote oral health. She envisions making a lasting impact by advancing research, prevention, and promotion efforts to alleviate oral health disparities. Please share your views and opinions on my posts.

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