I'm feeling really down about how yellow my teeth are (not helped by a snide comment from my mother), and I've tried to improve them in the last few months - whitening toothpaste and a new electric toothbrush - but I've found the only way to hide it is to keep my mouth closed when I smile. I hate it. The whitening treatments at both dentists in my town are too far out of my reach - around the £450 mark. I've avoided those places that offer really cheap whitening as I've heard that they're a bit dodgy, and not done by actual dentists. But I've just found one on Groupon for £79 (instead of £399) for LED whitening, which 'appears' to be carried out by dentists. I'm really tempted to have it done, but worried that it's dodgy - why such a massive discount? Am I being really naïve to think that it's ok?