Premium Mint Toothpaste with Fluoride and Peroxide. Rembrandt® came to be when a dentist decided to make a better toothpaste. He began by dreaming about papayas. There’s an enzyme in the papaya plant that naturally helps clean your teeth. This little enzyme, and a sprinkling of creative science, created something called Citroxain®. An entirely new way of caring for your mouth was born. At Rembrandt®, we believe having a healthy mouth goes beyond teeth and gums.We care about your entire mouth. It’s this mouth of yours that literally tells the world who you are. With a little love and care, it can be brilliant.