I have a dentist from South Africa (and a very cool one) who steered me away from one time bleaching and towards gradual bleaching with a mold for your teeth.
Basically the dentist makes the mold for you, then it's your part. He gave me Opalescence to actually whiten the teeth. I put in the mold over night, and after a few days it really did make a difference.
I've tried Opalescence 10% and 15%, although 15% can irritate the gums.
I would suggest seeing your dentist about the mold, get the first packages from him (or her) then order any more you need from amazon.com as it's very cheap from there.
Hope this helps.
Ps it's important to avoid tea, coffee or red wine during the time you're doing this - your teeth will be open for a couple of weeks afterwards, and that stuff will soak right in!
I also got given custom moulded trays to bleach my teeth at home, and a couple of tubes of the at home bleach. I haven't needed to use them yet- because the results were amazing. But if I need to in the future, I have the equipment, and I know it works too (though it takes longer)
Its expensive, but in my opinion, so worth it.
I guess that's the other thing- if you're doing it for a special occasion, even with the at home treatments, you need to give yourself some time to allow yourself to get used to it.
My dentist is in Emmenbrucke and I really recommend him. According to him the two treatments (dentist and night treatment) are very effective and complement eachother. Have not tried it myself yet (no cofee, no cigarretes have helped postpone it :P) but thinking of it!
Pming you his details in case you want to have a chat (&get costs- have no idea!)
Nadia
I think i paid round about 300 CHF including the first Opalescence
After that as mentioned I bought from Amazon.com - same product but far cheaper in the US.
All was professionally controlled and explained by the dentist. So doesn't that qualify as "by a dentist"
I am a dentist and specialized in bleaching and can maybe tell you in a few words that there is not only one way to bleach teeth. It can be done by the dentist in the dentists office (in-office-bleaching), it can be done at home befeore beeing instructed by a dentist (at-home-bleaching with mold and bleaching material, or without mold and with strips, so called white strips available in US and not that effective like other mentioned methods, but also working)
There is no evidence that additionally used lasers, heat etc make the method more effective.
Most important thing is: before bleaching a dentist must have checked teeth and fillings, if existent. For example gaps in fillings can be a contraindication for bleaching etc...
Hope I could help you.