MarketplaceOpalescence Tooth Whitening GelPosted on April 17, 2010. How long does tooth whitening opalescence last frost? I had some at the dentist last year and never used. I use it now and I wonder if it is still good or if it expires? It depends on whether or not you keep it in the refrigerator. Otherwise, I guess the power is down, but it will not hurt anything other than for the inconvenience. If it were me I give it a go since you already paid for it. Good luck! HELLO, CommentsThere are no comments.Leave a Comment | Popular My Friends |