19th century dentistry advertising trade cards. Ricksecker's "Perfection" tooth brushes, circa 1890.
Croll
Theodore P
TP
Department of Pediatric Dentistry, University of Pennsylvania School of Dental Medicine, USA.
Swanson
Ben Z
BZ
D000329:Advertising / Q000266:history*; D049672:History, 19th Century; D014099:Toothbrushing / Q000266:history* / Q000295:instrumentation; D014481:United States