Teeth become stained for different reasons. Some of them have to do with the foods and drinks you may consume, and there is also the natural ageing process, which makes the enamel of teeth less white. Thankfully, there are many options for teeth whitening in Singapore out there you can choose from, in order to deal with the intrinsic stains and extrinsic stains that your teeth develop.
Key Takeaways
Some of the main side effects that may occur are:
- gum irritation
- teeth sensitivity
- uneven whitening
- enamel erosion
- throat irritation
- temperature sensitivity (hot and cold)
- dry mouth
However, you also need to consider that many of the methods used to whiten teeth come with a number of risks and side effects. There is always a chance that the teeth whitening products you use to cause some problems, which you have to be aware of. Whether you practice teeth whitening at home with whitening products bought from the store, or you go to your dentist's office, you should inform yourself about the risks and side effects of teeth whitening so that you don't experience any negatives.
How teeth become discoloured
There are two major ways in which teeth discolouration works:
- Extrinsic stains - that is when foods, drinks, and smoking habits create teeth stains. The stains are on the outside of the tooth enamel and can be treated with whitening toothpaste that works on the outer layer of the teeth. Surface stains can also be removed with a host of whitening products that your dentist can recommend.
- Intrinsic stains - this type of discolouration occurs within the tooth. Medications, illness, irritated gums, the natural ageing process, and teeth trauma are all reasons why these stains occur. The best way to address them is to see a dentist for a tooth whitening treatment.
Three main ways to whiten teeth

There are three main teeth whitening methods that you can resort to:
- In-office whitening treatment
- At-home whitening products dispensed by your dentist
- Using over-the-counter products to whiten teeth on your own
- Natural teeth whitening methods
There are multiple factors at play when you choose which teeth whitening procedures to follow. There is the cost, your age, dental history, and treatment method involved in the process.
It is always good to first discuss with your dentist so that they can recommend a treatment plan and a whitening procedure that best suits your case. More importantly, they will know what method to recommend that best reduces the risk of any unwanted side effects.
What problems can teeth whitening treatments cause?
Some side effects of teeth whitening products are possible. Many over-the-counter products contain a bleaching agent, usually carbamide peroxide or hydrogen peroxide. Used correctly, these products can support the teeth whitening process and decrease stains.
However, there are also some risks associated with using these solutions, especially if you are careless and don't follow the instructions properly. Here are some of the risks you should be mindful of:
Gum irritation
It is not rare for a bleaching ingredient to cause gum irritation and in some cases even pain. It can range from mild irritation to bleeding gums. Such an issue is less likely to occur with a dentist administering the whitening procedure. However, products that you use at home for this purpose come with one size for all mouthguards, which are not as reliable.
When the mouthguard is not custom-made for your mouth, the product could end up leaking onto the gums and irritate them. The negative reaction depends on how concentrated the bleaching agent is and how long contact with it lasts. With higher levels of hydrogen peroxide in the product and possible mishandling, gum irritation and pain in the gum tissue is a serious risk.
Teeth sensitivity
When the bleaching agent soaks into the dentin of the tooth, it makes the nerves more exposed and vulnerable. Whitening products without a bleaching ingredient are safer and don't cause tooth sensitivity. Some over-the-counter products, like whitening gels, are at a greater risk of triggering increased tooth sensitivity.
One thing to remember about sensitive teeth after using tooth whitening products is that the effect should only be temporary. In most cases, tooth sensitivity lasts no more than 2-3 days after the whitening session.
Uneven whitening
Even when you are using the same whitening solutions, each tooth in your mouth can respond differently to the procedure. After all, teeth do have a different structure, which influences the end result. Teeth lacking in Calcium usually bleach more quickly than others. Additionally, if you have had any dental restorations, such as crowns and fillings, they may not respond to the whitening products at all. The product doesn't change the original colour of the implant, resulting in an uneven shade.
For this reason, it is usually better to consult with your dentist about a custom-fit tooth whitening system, in order to cover your teeth equally. In that regard, whitening strips don't always achieve the best result.
Enamel erosion
It is rare to experience enamel erosion due to a whitening effect, but it is still possible. It can be a direct result of the excessive use of bleaching agents. Most whitening formulae contain fluoride, Calcium, and Potassium nitrate, which are effective at preventing surface erosion and enamel loss. However, if the formula lacks these elements, there is a greater risk of enamel loss. The effect remains rare and mostly present in people with sensitive teeth.
The dentist you work with should be able to recommend a product that is safe to use and keeps the tooth enamel intact. The same applies to any product that they use in their whitening treatments.
Throat irritation
Throat irritation may seem strange to some, but considering you can ingest a small portion of the whitening solution, it is on the list of side effects. If this happens, you may feel your throat scratchy and sore for 1-2 days after using a whitening agent. It can even happen when you sometimes use whitening toothpaste. It should go away fairly quickly though. If it doesn't, you should speak with your dentist about the issue.
Temperature sensitivity
Whitening strips, gels, trays, and pens sometimes lead to increased sensitivity in teeth. It lasts for a day after the whitening treatment and then it fades away. Namely, it is mostly present in sensitivity toward hot and cold food and drinks. This is a side effect that occurs due to exposure to hydrogen peroxide, especially in the case of overuse of the said product.
Sensitivity toward hot and cold drinks and food goes away fairly quickly after the treatment. In some cases, it can be more severe, depending on the condition of the teeth and any other health conditions present.
Teeth dehydration/dry mouth
A lot of people don't link this side effect to teeth whitening, but it is always possible to experience this side effect. Tooth-bleaching agents like hydrogen peroxide and carbamide peroxide can dry out the enamel once they come in contact with it. That is because teeth are porous and substances penetrate there.
This side effect usually only lasts for several hours. If it is prolonged, you should contact your dentist immediately. If you are prone to dry mouth/xerostomia, you should always consult with your dentist first, before using any whitening gel or teeth whitening strips.
Related: After Teeth Whitening Tips to Maintain Results
Knowing more about the side effects of whitening treatments

Without a doubt, many of the products and procedures that you can turn to for the purpose of tooth whitening can lead to some side effects. Some of these unwanted side effects are minor and go away quickly, and some are rare and should be taken seriously.
In any case, it is always best to first consult with your dentist about teeth whitening treatments before you proceed to administer them. Whether it is an in-office treatment of intrinsic or extrinsic stains, there is some risk from the chemical reaction and mild abrasives used in the process that you best be aware of.
That said, let's see the potential side effects of some teeth whitening procedures and products.
Carbamide peroxide teeth whitening side effects
A lot of teeth whiteners contain carbamide peroxide. It is in many of the gels, pastes, and other products that your dentist may recommend. Unfortunately, an ill-fitting tray can often leave your gums irritated, especially if you already have gum disease. Custom-made trays are quite preemptive in this regard, but over-the-counter products don't come with any guarantee. They can come in contact with the soft tissues in your mouth and cause irritation.
Hydrogen peroxide teeth whitening side effects
If the whitening product contains a high concentration of hydrogen peroxide, for example over 3 percent, it can cause some damage to the teeth and the soft tissue in the mouth. The risk is greater if contact with a product containing this solution is prolonged and if you apply the product too many times. The most common side effect is teeth sensitivity, especially notable when consuming hot and cold foods.
Laser teeth whitening side effects
This is a modern method for whitening teeth. It is done in a dentist's office, but it doesn't come without risks. This is especially the case since people react differently to the procedure. Good oral health is very important before you attempt the procedure because it can lower the potential risks. It is possible to experience gum irritation, damage to the tooth pulp, tooth sensitivity, and even an increased risk of tooth decay.
LED teeth whitening side effects
Among the most common side effects of LED whitening treatments are gum and tooth sensitivity. According to studies, you may feel your teeth more sensitive for about a day after the procedure. There is also the fact that while the treatment shows promise in many, some people find the end result unsatisfactory. Additionally, it may not be as long-lasting as some of the other teeth whiteners (learn more about how long teeth whitening lasts). If you expose your teeth to a wide variety of staining foods and drinks, you will find yourself in need of a brighter smile in less than a month again.
Baking soda for teeth whitening side effects
Baking soda is one of the go-to products for dealing with stained teeth at home. But while it is finer than table salt, it is still an abrasive solution, which can lead to some enamel damage. Whether you use it alongside your whitening toothpastes or on its, you need to be very careful not to damage your teeth.
As a whitening method, it remains somewhat unproven, but with some risks for treating teeth stains. Whitening toothpastes usually contain abrasives too, but they are much safer and more proven than baking soda. That is why whitening toothpastes are preferred and generally a safer option than baking soda.
Whitening strips side effects
This oral health staple is usually safe, but there are some risks associated with frequent and extended duration of use. Soft tissue irritation and sensitivity are the most common complaints. Additionally, it is important to check the ingredients of the whitening product for potentially damaging components that can be quite harmful to teeth. In order to minimise these risks, you should consult with your cosmetic dentistry expert on what product is best to use for minimal risk.
Whitening pen side effects
Among all tooth whitening products, the whitening pen is quite popular. The goal of it is to whiten your teeth similar to strips, but it is easier to use because of the brush applicator it comes with. However, it too can make your teeth more sensitive on the first day after use. Another common side effect is gum irritation if you put the solution unwillingly on your gums. Overusing teeth whitening treatments like this at home can be more dangerous, as it can cause dry mouth, pain, and more.