NOthing goes to WAste (NOWA): A protocol to optimise sampling of ancient teeth

Advancements in archaeological sciences through innovative scientific techniques applied to ancient human remains have increasingly been transforming the study of the past. Destructive analyses of bioarchaeological or palaeontological specimens such as dental histology, isotopic or elemental analysis of dental mineralised tissues, 14C dating, proteomic analysis or ancient DNA are increasingly being applied to obtain ever more refined past life histories. In tandem with spatially-resolved analyses, mineralised dental tissues, especially enamel, have proven to be ideal archives. The main concern with any of these techniques is the need for some level of destructive sampling and thus damage to specimens. In compliance with the ALARA (As Low [damage] As Reasonably Achievable) principle, we present a standardised protocol (the NOWA protocol) for the optimisation, in terms of minimising the destructive approach, of tooth sampling for histology, biomolecular and biogeochemical analyses. The NOWA protocol enables the collection of multiple datasets through optimised sampling of a single dental specimen, ensuring the preservation of most of the tooth and, to a substantial degree, its morphology. Overall, this approach balances the significant scientific insights from such investigations against the inevitable conservation requirements of valuable archaeological and palaeontological specimens, thus maximising the feasibility of future analyses of individual specimens that need to be evaluated on a case-to-case basis.