IN MY EXPERIENCE IT IS A WASTE OF MONEY AND I AM ON MY WAY TO THE DENTIST! IT SO WEAKENED MY ENAMEL THAT I HAD 2 TEETH CRUMBLE AND I NEED 2 CROWNS!...AND OH YEAH - MY TEETH ARE STILL YELLOW!
I AM 65, AND IF YOU HAVE SENSITIVE TEETH AND WEAKENING ENAMEL BEWARE! THIS $24.95 JUST COST ME $$$THOUSANDS!