Ancient dentistry has been discovered in a 6,500-year-old human jawbone: a lump of beeswax that appears to be the earliest evidence of a dental filling.

The beeswax was probably applied to ease pain from a crack in the enamel and dentin layers of the tooth, said Claudio Tuniz, a nuclear paleoanthropologist at the Abdus Salam International Center for Theoretical Physics in Italy.

He and his colleagues report their findings in the journal PLoS One.

The details, based on this single finding, are fuzzy, said the study’s first author, Federico Bernardini, an archaeologist at the center....