How Long Will Opalescence Whitening At Home Last Opalescence Treswhite Supreme & Crest Whitestrips?

Opalescence Treswhite Supreme & Crest Whitestrips? - how long will opalescence whitening at home last

Well,
I am the teeth whitening ... is. The use of these two teams soon. After 30 minutes on the Supreme Treswhite, maybe I'm waiting 1 hours and with Crest Whitestrips. I wonder whether this is bad for your teeth? and perhaps also how long will it take before you notice a difference?

Thanks
-Karina