In recent years, professional teeth whitening has gotten quite popular. After all, the treatment makes enamel six to eight shades whiter in little time! However, did you know the field hasn’t always been this effective? It actually took thousands of years to reach its current form. Until recently, in fact, most of history’s teeth whitening amounted to trial and error. To learn more, here’s a summary of how this cosmetic procedure evolved to what it is today.