11 Things You Need To Know About Teeth Whitening

tooth whitening

Table of Contents

Have you ever felt self-conscious about the way your teeth looks?

For most people, the first thing they notice about others is their smile. A smile can truly brighten up anyone’s day and also gives you a confidence boost. Don’t worry, because you can achieve a bright and beautiful smile too!

Teeth whitening is a common procedure performed by dentists. It involves bleaching the tooth surface to reveal a lighter shade, making the tooth appear whiter. Below are some answers to your questions about this treatment.


1. Causes of Tooth Discolouration

Common tooth stains

There are 2 types of tooth staining: extrinsic stains and intrinsic stains.

Extrinsic stains are surface stains on the enamel, which is the outermost layer of a tooth. It can be caused by factors such as:

  • smoking
  • poor oral hygiene which builds up yellow/ brown calculus
  • frequently drinking liquids such as coffee, tea or red wine
  • taking iron supplements through the mouth


Intrinsic stains are stains that affects the deeper layer of teeth (dentin) or due to abnormalities or interferences of tooth structure formation. Some common causes include:


  • fluorosis (white/brown patches on the tooth surface when there is excess fluoride intake while the child’s teeth were still developing)
  • prescribing certain antibiotics such as tetracycline to children with teeth which have not completed developing
  • dead tooth from trauma
  • congenital diseases such as cystic fibrosis

Age can also play a role in teeth discolouration.

This is because the enamel wears down and thins out, revealing the naturally yellow dentin below.


2. How to Choose the Best Teeth Whitening Treatment for You?

The best whitening treatments would depend on the type of stains.

Extrinsic stains are usually removed by the routine scaling and polishing treatment whereas intrinsic stains are more stubborn and tougher to get rid off.

Intrinsic staining requires teeth whitening treatments from a dental professional.


3. How Does Teeth/Tooth Whitening Work?

Bleaching agents such as hydrogen peroxide or carbamide peroxide have the ability to penetrate into the enamel to target the staining.

Bleaching agents introduces oxygen to the stained compound and breaks it up into smaller fragments which are not pigmented. This reduces staining and allows the tooth to appear whiter.

In Singapore according to the SDA, a registered dental practitioner is permitted to use 6%-35% hydrogen peroxide legally for teeth whitening treatments.

A dental practitioner is also allowed to prescribe up to 6% hydrogen peroxide to the patient for home use and other over the counter whitening products (such as toothpaste) are only permitted to have up to 0.1% hydrogen peroxide.

Bleaching agents with more than 10% hydrogen peroxide can be corrosive so if you opt for commercial OTC whitening kits, the concentration would be much lower than what you get at a dentist’s.


4. Is Teeth Whitening Safe?

Professional teeth whitening is generally safe and effective.

It should only be carried out by a dentist or another trained dental professional. Some aestheticians may offer teeth whitening services but it may put your oral health at risk as they do not have professional training.


5. Side Effects of Whitening Treatments

However, there are minor side effects attached to this treatment.

Tooth sensitivity and gum irritation may be experienced after the whitening procedures.

These side effects are usually temporary and will go away in a few days. These can be prevented with proper usage of the bleaching agents and minimised by the application of desensitising gel or toothpaste in your mouth.


6. How Can You Whiten Your Teeth?

There are 2 methods to whiten your teeth: In-office teeth whitening or take home whitening kit.

In office whitening

In-office whitening is done by dentists in the clinic.

The results are instantaneous.

The dentist would carry out scaling and polishing first, then put on a dental dam to protect your gums and apply the bleaching gel on your teeth.

A bright light will be shined into the mouth to activate the bleaching agent and accelerate the process. This whitening procedure offers fast results, but it is more costly and you may experience more tooth sensitivity.

Custom fit whitening tray

For the take-home teeth whitening kits, the dentist will take a mould of your teeth to make custom fit trays.

The dentist will then issue the tray along with whitening gel tubes (such as Opalescence take home teeth whitening gel) and instructions of how to whiten your teeth with it in the comfort of your own home.

These instructions include how to apply the whitening gel on the tray and how long or often you would have to wear it for.

For this procedure, you would be able to lighten the shade according to your preference as it is a gradual process that could take weeks. Sensitivity experienced would also be milder as the concentration of the whitening gel is lower for take-home whitening kit.

7. How Much Improvement to the Whiteness Can You Expect to See?

After the whitening procedures, you should be able to see a difference of 2 to 4 shades lighter than your current smile.

Some clinics offer the Philips Zoom in office whitening option where you’d be able to see results of up to 8 shades lighter in the span of an hour.

Philips zoom whitening

However, the results do vary for each individual person and each individual tooth.

For some patients, the treatment may not work at all and others may see a significant change in their tooth shade.

Bleaching only works for natural teeth. It does not affect other fillings, dentures, veneers or dental crowns in the mouth.


8. How Can You Maintain Your White Smile After Treatment?

The effect of teeth whitening is not permanent.

The duration of its effects vary from individual to individual so it is impossible to give a precise duration.

Usually, the effects can last from months up to a year depending on dietary and lifestyle habits. If you enjoy drinking red wine or coffee, the effect is not going to last so it is advisable to modify your existing habits to avoid future stains and enjoy a brighter smile for longer.

The use of a straw for sipping coloured drinks is recommended. Good oral hygiene is also important to maintain whiteness.


9. Can You Treat a Single Dark Tooth?

There are 2 main reasons for a single dark tooth: a previously root canal treated tooth or a tooth that has suffered from dental trauma.

This is caused by the dead pulp tissue bleeding into the dentine.

For this situation, the dentist would recommend an internal non-vital bleaching.

The dentist will drill a small hole at the back of your tooth and insert the bleaching agent into the hole.

Then, the hole will be filled and you’d be asked to return the following week to repeat the procedure until it reaches your preferred tooth shade. This may take up to 3 or 4 weeks.

However, this treatment may not work at all. If there is no change, the dentist may consider a veneer or a crown to cap the tooth.


10. Are Yellow Teeth Considered Healthy?

Yellow teeth are not considered ideal to most people.

But, did you know that the tooth’s dentin is naturally yellow in colour while the enamel is translucent?

This is why the yellow tinge of teeth is perfectly normal and are considered healthy.

However, if the yellow colour is caused by calculus or staining from certain beverages or smoking, it can be removed to improve your smile.


11. Are Home Remedies for Teeth Whitening Effective?

how to whiten teeth

Whitening toothpastes contains mild abrasives and chemicals that can help remove stains off teeth and result in whiter smile.

However, prolonged use would strip down the enamel layer and cause sensitive teeth and tooth decay.

Other teeth whitening products such as brushing with baking soda, apple cider vinegar and turmeric are not proven to help with whitening teeth as there is no evidence that it would work to give you a whiter teeth.


If you have noticed yellow stains on your teeth and are unsure of the causes, do not hesitate to drop by so we can take a look for you. Our dental professionals at Ocean Dental would be happy to explain the treatments available.

We aim to provide the best service for a healthier and brighter smile so you would feel confident with your pearly whites! Schedule an appointment or check out our professional teeth whitening services in Singapore!