This study investigates the use of dental calculus for paleodietary studies using stable isotope analysis of a skeletal sample from the Greek colonial site of Apollonia Pontica, Bulgaria (5th to 3rd century BC). A sample of 27 individuals was used to examine the δ13C and δ15N values of paired dental calculus and bone samples, and the dental calculus was analyzed as separate organic and inorganic components. No significant correlation was found between the δ13C values of either the bone collagen and organic dental calculus samples, or the bone apatite and inorganic dental calculus samples. A significant correlation was found between the δ15N values of the bone collagen and organic dental calculus samples; however, the reason for this correlation is unclear. A greater range of variation in the δ13C and δ15N values was found in the organic dental calculus samples compared to the respective bone collagen samples. These results suggest that dental calculus is not an appropriate proxy to bone for paleodietary studies using stable isotope analysis and that any dietary signal is clouded by other data. The oral microbiome is considerably diverse and is the most probable explanation for the great range of stable isotope values obtained from dental calculus. A significant, strong correlation was found between the C/N ratios and δ15N values of the organic dental calculus samples, suggesting that the lowest C/N ratios and δ15N values depict deposits with the least bacterial alteration.
Author Keywords: carbon, dental calculus, nitrogen, paleodietary studies, Social Sciences, stable isotopes