What you should know about bleaching.

teeth bleachingTeeth can become dark through either external stain from smoking and diet, or from internal discolouration from age and nerve death. External stain can be removed with professional polishing and can be minimized with the regular use of “whitening” toothpaste. Internal colour can now be removed with the use of chemical bleaching products.

All bleaching products work in the same way to break down the stain molecule within the tooth. Their effectiveness varies with the concentration of the bleach, hydrogen peroxide and the amount of time that it is applied to the tooth. As far as we know, no damage is done to the teeth by their exposure to hydrogen peroxide, but the teeth may become temporarily more sensitive to cold during the bleaching procedure.  Hydrogen peroxide may be a co-carcinogen because of it’s free radicals. Please contact Dr. Schenk if you have any questions in this regard.

It is best to start bleaching after having a professional cleaning. Avoid eating stain causing foods and smoking while bleaching. Only enamel can be whitened through bleaching.  Root surfaces, areas where the enamel is worn through, fillings and crowns will not change colour. Any dental work visible when smiling will likely have to be replaced after bleaching.

Currently, we use two different products in this office. They vary in their effectiveness, number of teeth bleached and cost.

Crest Professional White Strips

Like the over-the-counter strips, these are easy to apply. They will lighten the front 6 teeth top and bottom. The clear cellophane strips are applied to the teeth twice a day for ½ hour and the kit provides strips for 3 weeks. The concentration of bleach is higher than the over-the-counter strips.


For people that have a wide smile, deep discolouration to their teeth, or want their teeth the whitest that they can be, a system using a bleaching gel in a custom plastic tray is used. This is placed over your teeth at night for up to 3 weeks.

The natural colour of the teeth does return slowly with time, therefore the results will need to be touched up time to time. The colour change can be monitored during checkups by comparing the teeth to a standard colour guide.


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