Extraction of Opal Phytoliths from Herbivore Dental Calculus

Dental wash: a problematic method for extracting microfossils from teeth

“…In contrast, a former study that employed a similar method reported only the recovery of siliceous plant remains (Middleton and Rovner, 1994). In addition, microfossil studies on lithic instruments (Piperno and Holst, 1998;Piperno et al, 2000;Barton et al, 1998) reported much lower concentrations of starch than we found in the human teeth.…”

“…In addition, microfossil studies on lithic instruments (Piperno and Holst, 1998;Piperno et al, 2000;Barton et al, 1998) reported much lower concentrations of starch than we found in the human teeth. Besides that, the number of phytoliths found in both our teeth samples was lower than that observed in samples from individuals of the late Roman period (Fox et al, 1996), in teeth of an extinct ape (Ciochon et al, 1990) and in herbivore teeth (Middleton and Rovner, 1994). The concentrations of phytoliths in our samples were also very small when compared to that of the starch grains of these same teeth.…”

“…An innovative approach to the study of ancient diet is the analysis of dental calculus ( Fig. 1) (Middleton and Rovner, 1994;Fox et al, 1996;Nelson, 1997;Reinhard et al, 2001a,b).…”

“…However, in this case, not the residues, but instead, the cleaned tooth is analyzed. Here we analyzed the residues that were left in the acid solution after the wash, using a similar method to that described by Middleton and Rovner (1994). However, we applied the method to human teeth, not to animal teeth like these researches did.…”

“…Another difference is the acid concentration. While Middleton and Rovner (1994) used a 10% concentration of hydrochloric acid to warrant dissolving thick dental calculus deposits of herbivore teeth, aiming the extraction of phytoliths, we used only a 4% acid concentration, as we wanted to wash thin dental calculus deposits off human teeth and were concerned about avoiding dental damage. Finally, and most importantly, the goal of this analysis was to determine how many microfossils are trapped in dental calculus.…”