I have what I think is the best kept tooth whitening secret ever. Dentists will kill me for revealing this to you, but I can't hold back. Recently, I was getting my teeth cleaned and I asked about the teeth whitening programs they offered. They have the one hour "laser" treatment that happens while you are at the dentist, or the take home method where you get something that looks like my old lacrosse mouth guard and you fill it with this solution that will whiten your teeth. You put the mouth guard on for a period of time in the comfort of your home and volia, your teeth are whiter. Either way you go, it costs $600! I told the dentist that I thought that was way too expensive and she told me that most dentists charge over $700! I knew I could never afford that, but my teeth are browning from all the coffee I drink so I went over to CVS and bought a $20 Rembrandt teeth whitening kit. You mold the mouth guard yourself and use their gel to whiten. I tried it and it did absolutely nothing for my teeth. I thought that was $20 down the drain until the lightbulb went off! Next time I was at the dentist and I asked how much the gel would cost if I already had the mouth guard (thinking of my cheap $20 mouth guard from my Rembrandt kit). The dentist said, "if you already have the mouth guard and you just need the gel, it's $60." So instead of $600, it's $60?!?! I decided I had to go for it and I did. Within one treatment my teeth were much whiter. It's definitely a stronger formula than the OTC stuff, so it worked wonders and it didn't cost me an arm and a leg and a tooth!