Teeth Whitening Patient Information Leaflet

Tooth whitening or bleaching is a very safe and effective way of lightening the teeth. In the UK, it is illegal for anyone other than dentists to carry out tooth whitening. Prior to tooth whitening a full examination should be carried out, as it will not be suitable for everyone and your dentist can discuss other options with you. If you have any white fillings on your front teeth, they may need to be replaced after whitening to match the new shade, as the bleach will not affect them.


Your dentist will take impressions of your teeth so that special trays that fit your mouth can be made. When the trays are ready you will be given them along with a gel containing 16% Carbamine Peroxide and a syringe. A small amount of gel is syringed into the trays, which are then placed over your teeth, normally overnight but at least for 2 hours each day. In most cases a good result will be achieved in 2-4 weeks but it depends on the nature and severity of the staining. Your dentist will monitor your progress during this as much as they think necessary. During treatment it is best to avoid foods and products that may stain the teeth such as nicotine, red wine, coffee, curry etc. This is because your teeth are more porous during bleaching and absorb stains easily. You should expect the results to last at least 2 years, but it is often longer in many cases. Bleaching will be less effective if you smoke or eat/drink products that cause tooth staining. The bleaching trays can be kept and re-used in the future as long as your mouth has not altered significantly.


Between 15-65% of patients experience sensitivity during treatment but this can be managed in most cases, usually by stopping bleaching for one or two nights before continuing.


If you have any other questions, please speak to your dentist who will also give you an estimate of the cost of treatment.

Instructions for use

  1. Brush your teeth thoroughly and floss as normal.

  2. Remove the tip from the syringe containing the carbamide gel and extrude a little of the contents of the syringe into the appropriate parts of the tray towards the deeper and front parts of the tray.

  3.  Place gel in the tray on the cheek and the tongue side of the back teeth.

  4. Seat the tray over the teeth and press firmly.

  5. A finger, a tissue, or a soft toothbrush should be used to remove excess gel that will flow beyond the edge of the tray.

  6. Rinse gently and do not swallow. The tray is usually worn whilst sleeping, but as long as it is worn for AT LEAST 2 HOURS this will be effective.

  7.  In the morning remove the tray and brush the residual gel from the teeth. Rinse out the tray and brush it, Store it in a safe container.

  8. Do not eat, drink or smoke whilst wearing the bleaching tray.

  9.  Carbamide peroxide should not be exposed to heat, sunlight, or, extreme cold.