Cleaning protocol of archaeological dental calculus: A methodological proposal for vegetable microremains analysis

One of the major drawbacks involves the contamination produced during the sampling of dental calculus samples due to their manipulation with non-sterilized latex gloves containing maize starch. These gloves have been commonly used for the sampling, cleaning and conservation of archaeological materials. The objective of the present work is to propose a protocol for the cleaning of dental calculus samples that have been contaminated, allowing the removal of such material from the calculus surface. The application of this protocol guarantees the exogenous elements elimination without causing the loss of the archaeological material, since as it is a nondestructive and/or invasive cleaning method, it remains contained within the dental calculus which protects and guarantees its preservation.

Fifty-seven fragments of dental calculus were recovered from several archaeological sites in the province of Córdoba, Argentina, dated by AMS between 4058 and 387 14C years BP. A sample comprising 22 fragments larger than 2 mm, which represent 38.59% of the total, were subjected to four cleaning stages through distilled and centrifugal water. As a control test, 10 fragments of human dental tartar were taken, known to have not been previously handled with powdered latex gloves.

The results show significant differences between the four cleaning stages, representing an important reduction of modern starch grains adhered to the surface of archaeological samples of human dental calculus.