ProtecSom®’s anti-dust mite covers are complete covers, that completely enclose bedding elements. They form an impenetrable barrier for dust mites allergens. The wear condition of your bedding elements has no importance. So, it is not necessary to buy a new mattress. However, before installing your cover, vacuum your mattress carefully (by means of a vacuum cleaner equipped with a filter HEPA) while making sure to ventilate thoroughly the room where it is located before, during and after this operation.