I've been excavating the same site for the past 2 years and so far this is what I have to show in the category of dental hygiene (dating from the 1890's to turn of the 20th century).
One bone toothbrush inscribed 'AKIBA WARRANTED PERFECT', and one milk white glass tooth powder dispenser marked...
I was digging for bottles in a new site last year when I found the lid to a stoneware toothpaste tub. It has the Imperial Crest of Queen Victoria on it as well as the words "by appointment" under it. I did some research and found out the "by appointment" designation means the product was in use...