In Italy archeology discovered ancient seals. According to experts, their age can be about 12 thousand years.
Scientists noted that the ancient seals were made from bitumen, visually resembling resin. Despite this, it had a more dense structure, which in its solidified form was similar in strength to the stone. Even then, metal tools were used to install the seals.
Ancient seals perform the same functions as modern ones. Due to the fact that they were poured into the teeth in the molten form, they also densely covered the enamel, not missing the external stimuli to the nerve endings.
A special chemical composition also made it possible to get rid of the danger of developing infections in the oral cavity. Archaeologist from the University of Bologna Stefano Benazzy noted that this find is special, as the discovered seals differ from the ancient analogues.
They could hardly be used now, because the installation process itself was very painful. Previously, the world's oldest seals were artifacts found in Slovenia. Their age was about 6.5 thousand years.