Archaeologists working in northern Vietnam have found chemical evidence that people were permanently blackening their teeth around 2,000 years ago. The study focused on human remains from the Dong Xa site, dated to the Iron Age and linked to the wider Dong Son cultural sphere. By analysing the surface of ancient enamel, researchers identified traces of iron compounds consistent with deliberate cosmetic treatment rather than natural staining. The results offer the first clear scientific confirmation that tooth blackening was already established in Vietnam two millennia ago. The findings also suggest that the technique relied on iron salts, likely mixed with plant materials rich in tannins, to create a deep, glossy black surface that altered the appearance of the teeth.
