Teeth whitening helps restore teeth to a shiny white colour through the use of bleach. Why causes teeth to turn yellow?  Our teeth can discolour through the years as our enamel wears down. The wearing down of enamel allows dentin, a yellow color substance that makes up the core of our teeth, to show through. This is what gives our teeth a yellowish tint.  Best way to whiten teeth at home?  The best way to whiten teeth is to use a professional whitening kit. The kits can be purchased from your dentist for use at home. The strength of the gel used in these kits is lower than that used for in-office bleaching. Therefore, the gel can be applied for longer periods of time. Usually the custom made trays are worn a couple hours a day or overnight for a few days or weeks depending on the product.  Some of my teeth are more yellow than others You can selectively whiten those teeth until they become the same shade as the rest of the teeth! The other advantage of this system is that if patients wish to whiten their teeth in the future, additional whitening gel can be purchased for a fraction of the cost since the bleaching trays can be used indefinitely (as long as they still fit).  Is In-Office Whitening right for me?  We do not recommend in-office whitening for a few reasons.  There is a risk for increased sensitivity, as the strength of the solution used is much higher than the at home solutions.  The cost of in-office bleaching is about 3X that of professional at home kits. Does not offer predictable shade results and you may end up needing a second appointment to achieve the result you want.