Whitening is intended primarily to whiten natural tooth bone. Several customers have also told us that it had made plastic seats whiten several degrees. Age is no obstacle / problem for bleaching, but it should be noted that the 50-year-old's teeth have had considerably longer time to get dirty than for example 20-years-old’s. In other words, needed more treatment sessions in order to achieve the same results. Also 70-80 years our customers have been satisfied with our products!