laser teeth whitening cancerous? and best mattress opinions!

yes, i realize both are extremely different subjects, but i didnt want to flood up the board with seperate posts
first off, my dentist wants to give me free zoom laser whitening to follow up with my completion of invisaligns
but...im afraid of saying yay or nay because im wondering if it could cause damage in the future|? that stuff kinmda...freaks me out
or is the laser totally safe|?


hmmm

also, is the temperpedic really good for your back|? i just want something thats going to give my body the support it needs. im a massage tehrapist and never want to suffer with the back pain some of my clients do|!
thank you|!