Excellent product
The trays work well if you read the instructions on proper way to apply.  I had a temporary bridge and wanted to whiten my natural teeth before permanent teeth were placed.  My natural teeth whitened several shades lighter and my bridge which was matched to my natural teeth.  The color difference was shocking after 3 applications.  My bridge looked terrible. My bridge was changed out to match my improved white natural color.  I am incredibly excited about the product.  It is a great product.  If you don't apply the tray correctly on your teeth you will end up with a melted mess of whitener on your teeth.  If you place the tray on your teeth and "suction the tray" on your teeth (first) the liner of whitener will adhere to your teeth and the tray is removed.  Please do this to ensure a great whitening result!  My spouse uses the syringes but I like the fast 20-minute treatment.  Dramatic whitening results.
Rating: 5 stars