At some point, most of us have probably been told by the dentist that we need to brush more as we have dental plaque building up. But what is dental plaque and what could it tell us about ancient humans?
Dental calculus (plaque) is ubiquitous on modern human teeth; it forms when a biofilm of oral bacteria builds up on the teeth and calcifies. As calcium phosphate mineral salts deposit on the tooth surface the biofilm becomes ‘trapped’ and preserved (Weyrich et al. 2015). This happens constantly over the individual’s lifetime trapping layer upon layer of bacteria. While dental plaque is often discarded from both live and dead individuals it is now recognised that this plaque contains bacteria that can be identified. Luckily for us ancient (and modern) hunter-gatherer groups don’t brush their teeth!