Evaluating microfossil content of dental calculus from Brazilian sambaquis

To date, limited numbers of dental calculus samples have been analyzed by researchers in diverse parts of the world. The combined analyses of these have provided some general guidelines for the analysis of calculus that is non-destructive to archaeological teeth. There is still a need for a quantitative study of large numbers of calculus samples to establish protocols, assess the level of contamination, evaluate the quantity of microfossils in dental calculus, and to compare analysis results with the literature concerning the biology of calculus formation. We analyzed dental calculus from 53 teeth from four Brazilian sambaquis. Sambaquis are the shell-mounds that were established prehistorically along the Brazilian coast. The analysis of sambaqui dental calculi shows that there are relatively high concentrations of microfossils (phytoliths and starch), mineral fragments, and charcoal in dental calculus. Mineral fragments and charcoal are possibly contaminants. The largest dental calculi have the lowest concentrations of microfossils. Biologically, this is explained by individual variation in calculus formation between people. Importantly, starch is ubiquitous in dental calculus. The starch and phytoliths show that certainly Dioscorea (yam) and Araucaria angustifolia (Parana pine) were eaten by sambaqui people. Araceae (arum family), Ipomoea batatas (sweet potato) and Zea mays (maize) were probably in their diet. (C) 2009 Elsevier Ltd. All rights reserved.

Efficient but destructive: a test of the dental wash technique using secondary electron microscopy

The Boyadjian et al dental wash technique provides, in certain contexts, the only chance to analyze and quantify the use of plants by past populations and is therefore an important milestone for the reconstruction of paleodiet. With this paper we present recent investigations and results upon the influence of this method on teeth. A series of six teeth from a three thousand years old Brazilian shellmound (Jabuticabeira II) was examined before and after dental wash. The main focus was documenting the alteration of the surfaces and microstructures. The status of all teeth were documented using macrophotography, optical light microscopy, and atmospheric Secondary Electron Microscopy (aSEM) prior and after applying the dental wash technique. The comparison of pictures taken before and after dental wash showed the different degrees of variation and damage done to the teeth but, also, provided additional information about microstructures, which have not been visible before. Consequently we suggest that dental wash should only be carried out, if absolutely necessary, after dental pathology, dental morphology and microwear studies have been accomplished. (C) 2010 Elsevier Ltd. All rights reserved.