"Indexo" finger toothbrush, in plastic box, with instructions, by the Indexo Co. Inc., New York, USA, 1901-1925

The ‘Indexo’ toothbrush is made entirely of rubber, which has been shaped to fit over the index finger. The bristles are used to brush the teeth. At a time of growing interest in personal dental hygiene, this object represents a novel departure from the standard toothbrush and was perhaps intended as the travel toothbrush of its day.

Other toothbrushes of the same period were made from horse hair or wild boar hair. Nylon bristles were introduced in 1937. Daily cleaning of the teeth was not a regular habit until the early 1900s. In England and the United States, toothbrushes were provided to all servicemen during the First World War, which helped popularise their use.