Kent is a brand of cigarettes first to introduce smoke filters in 1952.The original version of the Kent Micronite cigarette filter used crocidolite, a form of asbestos, from 1952 until at least mid-1956 which was known at the time to be a cause of cancer.Three years later Lorillard introduced "New Kents" with a new Micronite filter, this time asbestos-free.