Teeth whitening at home smiling brunette

A Guide to Teeth Whitening with Trays

Below is a quick overview of the steps you should follow to whiten your teeth. This information is beneficial for reviewing the best practices for whitening your teeth.

Discipline is key when whitening your teeth. We can administer the whitening gel to you, but we cannot perform the procedure. It requires diligence to be consistent every day until the treatment is complete to receive the desired results.

By the same token, avoiding overusing the whitening gel is also essential. If you use the trays, for example, multiple times on the same day, you could very easily damage your teeth.  

Teeth whitening is very safe and effective if you follow these simple instructions.

  1. Brush, floss and rinse before placing in the whitening trays.
  2. Place a small water droplet amount of gel into each tray on the inside surface that faces the cheeks. Do not put any gel on teeth with crowns or veneers; these porcelain surfaces will not whiten, and you will just be wasting your gel.
  3. Seat the tray with the gel around the teeth.
  4. Wipe away excess gel in the mouth with a finger, tissue or a Q-tip. For whitening treatment, wear the trays for 45 minutes a day. After treatment, remove, rinse and brush the trays with a toothbrush with cool water. Spit out excess whitening gel and rinse vigorously.  
  5. After 30 minutes, brush your teeth as usual. For sensitive teeth, Sensodyne or Colgate-sensitive toothpaste will help reduce temperature sensitivity.  
Placing teeth whitening gel in trays
Whitening Gel - Droplet amount on inside surface toward cheek for each tooth

{Optional treatment} MI remineralizing paste or ACP Paste is a product that recalcifies teeth after the whitening process: Apply paste with your finger to the fronts of your teeth, insert the whitening trays and leave on for 15 minutes. Remove the trays, and spit to remove the excess paste. Do not rinse. Make sure the whitening trays are clean and dry before you place the trays back into their protective case. Do not use MI paste if you have a casein allergy.


The number of days required to obtain the desired results will vary between individuals from a few days to two weeks.


  • Do not eat, drink or smoke with trays in.
  • Try not to eat or drink for 1 hour after treatment. Food or drinks containing strong colours, like coffee and red wine, should be avoided for at least 48 hours after the treatment period or consumed in moderation.
  • Brush after every meal to reduce the risk of staining. Do not use any type of charcoal toothpaste.
  • Do not smoke immediately after treatment. Wait for at least 2 hours.
  • Use whitening gel at room temperature. Store in a cool place out of direct sunlight at temperatures between 2-25°C.
  • If you end up not using all the whitening gel it can be kept in the fridge to extend the shelf life.
  • Some people will need to touch up results every 6-12 months while others may only need to every 2-3 years.
  • Teeth may become sensitive for some individuals. You can use sensitive toothpaste or discontinue use on sensitive teeth. Sensitivity typically will resolve 24-48 hours after you stop using the whitening gel.
Sensodyne toothpaste and prorelief toothpaste


  • Keep out of reach of children and pets.
  • Whitening is not recommended for pregnant women or children under 14 years old. We want to wait until all the permanent teeth are in.
  • No studies have shown any adverse effects during pregnancy but follow as a precaution. Breastfeeding mothers can use the whitening gel and the MI/ACP pastes. There are no contraindications.


  • Eye (contact): Wash thoroughly with water and seek medical advice if symptoms develop
  • Skin (contact): Wash thoroughly with water and seek medical advice if symptoms persist
  • Ingestion (large amount): Drink plenty of water and seek medical attention
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Dr. Gurpreet Sidhu - Dentist at Lighthouse Dental Centre and Blue Water Dental
Dr. Gurpreet Sidhu

With nearly two decades of experience, Dr. Sidhu enjoys helping his patients learn about dentistry. Knowledge is meant to be improved, challenged and shared.

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