Bests & Worsts Reviews from Amazon

I've only used 5 of the trays so far, but 2 were damaged or defective. After emailing with the manufacturer (because the seller stopped replying to my emails) I learned that this product is only authorized to be sold at Dental Offices. Any Amazon seller selling this product is unauthorized, and the manufacturer will not guarantee the product. Please do not buy this product online and waste your money on a defective product. And after 5 uses, I have not seen results, other than some minor tooth sensitivity.