Professional take-home teeth whitening kits available from your dentist contain a high concentration of hydrogen peroxide or carbamide peroxide and provide excellent results in 1 to 2 weeks of prescribed use. Custom-fit trays keep the whitening solution on the surface of the tooth to be whitened. Impressions are taken of your upper and lower teeth and sent to the dental laboratory to make your trays. It will normally take 1 to 2 weeks for the dental lab to make your trays. The initial shade of your teeth is recorded in your dental chart for comparison when whitening has been completed. An appointment will be made to show you how to dispense the teeth whitening solution in the trays and give you detailed instructions to follow. Take-home teeth whitening is typically used one hour a day for two weeks, and can be used for touch-up applications thereafter. Whitening times typically take 2 weeks, but can take longer for those with darker stains.