Birch bark tar has antiseptic properties, scientists say
Sarah Pickin, 23, found the lump of birch bark tar while on a dig in western Finland.
Neolithic people used the material as an antiseptic to treat gum infections, as well as a glue for repairing pots.
Ms Pickin's tutor, Professor Trevor Brown, said: "It's particularly significant because well defined tooth imprints were found on the gum."
He explained: "Birch bark tar contains phenols, which are antiseptic compounds."
Ms Pickin, who was one of five UK students on a volunteer programme at the Kierikki Centre on the west coast of Finland, said: "I was delighted to find the gum and was very excited to learn more about the history."
She added: "I am keen to work in this area in the future so the experience has stood me in good stead."
The archaeology student also found part of an amber ring and a slate arrow head which will be on display at the centre following laboratory analysis.
While Neolithic people chewed gum to treat infection, a spokesman for the British Dental Association said chewing sugar free gum after meals stimulates saliva which offers protection against tooth decay.