Photo: Stefano Benazzi

A pair of teeth found near the village of Lucca in northern Italy show evidence of the oldest known dental fillings.

The teeth were upper central incisors, and belong to the same person, who lived during the Upper Paleolithic era.

The cavities in the teeth extended from the surface all the way through to the pulp.

A variety of microscopic techniques were used by University of Bologna researchers to get a detailed look inside the holes.

Numerous horizontal marks on the walls of the teeth were observed, suggesting the cavities were drilled and enlarged, most likely with small stone tools.

The team found traces of bitumen in the cavities, which is a semi-solid form of petroleum now commonly used in road construction and as a sealant on roofs. The researchers believe the bitumen was used as an antiseptic of sorts, and prevented food from entering, similar to modern dentistry techniques.

Plant fibers and hairs were also found in the holes of the teeth, and were embedded at the same time as the bitumen filling.

The horizontal markings on the teeth resembled similar ones found on 14,000-year-old teeth unearthed on another Italian site by the same research team. The older teeth are the first known example of dentistry in humans, but did not contain bitumen like the more recent discovery.

The findings were published in the American Journal of Physical Anthropology.