People of the ancient Maya culture perhaps had some of the fanciest smiles in human history, often adorning their teeth with colorful and precious jewels and rare metals, from volcanic obsidian glass and vibrant green jade to glistening gold. 

A new study, published in the Journal of Archaeological Science: Reports, has taken a look at this intriguing practice and concluded that it might not just have been an aesthetic choice or a display of wealth – the powerful sealant used to bind the precious stones to the teeth may have also reduced the risk of oral infections and improved dental health. 

Scientists at Mexico’s Center for Research and Advanced Studies of the National Polytechnic Institute studied eight teeth from the 1st millennia CE found in modern-day Honduras, Guatemala, and Belize to learn more about the material used to “glue” the inlays onto the tooth.

Clearly, this was a strong adhesive. The teeth date to the Classic Maya Period (from approximately 250 CE to 900 CE) and the inlays are still tightly attached to the tooth. Beyond this strength, it also looks like the sealant might have also contained organic compounds that held some antiseptic value. 

“Using selected vegetal resins or essential oils in the dental sealings could well provide the antibacterial, antifungal, and anti-inflammatory activities, necessary to ensure successful treatments and thus prolong the lifespan of the inlay in the mouths of their human carriers,” the authors write.

The sealant was composed of some 150 organic molecules that are commonly found in plant resins. For instance, one of these compounds is sclareolide, a natural product derived from Salvia plants that is known to have antibacterial properties. Another is camphor, a waxy solid that can be applied as a topical medication to treat bug bites and skin irritation. Even today, you can find camphor in a variety of skincare lotions and bath products due to its soothing properties. 

Interestingly, it appears that these flashy dental accessories were not only worn by the wealthy elite as a gaudy display of wealth or social prowess.

"Two individuals were recovered from a formal tomb or crypt, though the lack of prestige offerings directly associated with these individuals suggests they were not of royal status. Another five individuals were from simple internments and likely reflect individuals of relatively modest social standing. An additional tooth from Holmul had been part of an offering," the study authors write.

"While the blends were both complex and effective in providing long-lasting dental obturations, the mortuary contexts of the individuals sampled indicate these were not elite individuals but that instead, a broad swathe of Maya society benefited from the expertise of the individuals who manufactured these cements."