Microbiology of Dental Calculus of Prehistoric People from Cabeçuda Shell Mound, Santa Catarina, Brazil

Background and Aim: Oral health investigations contribute to the understanding of the culture and biology of past populations. It is possible to go beyond the main diseases, such as caries and tooth loss, addressing detailed information on morphology, pathology, and physiology. A progressing analysis of microfossils in dental calculus confirms the good preservation of biofilm in the matrix. Health models associating synergic relationships of dental & oral pathology with systemic diseases are important to understand modern, as well as past human life and death. The aim of this investigation is to the absence of dental caries in one human past population, that could be associated with a specific oral microbiota and health conditions. Methodology: Dental calculi were extracted from the human teeth of 20 different adult and subadult individuals, both sexes. The morphology of biofilm components was described, especially in the search for Vibrio. Coastal human groups lived exposed to the saltwater environment, and the one studied here, from the shell mound of Cabeçuda, Santa Catarina State, Brazil, was free from caries (estimate date 2,800 to 1,500 BP). The archaeological series belonged to the Museu Nacional of Rio de Janeiro; sample selection occurred in its Biological Anthropology laboratory. Calculi extraction & preparation was in the laboratory of paleoparasitology at Fiocruz, the SEM analysis was at Hertha Mayer Laboratory, Federal University of Rio de Janeiro. After appropriate hygienization, dental calculi were extracted and disaggregated, and parts were scanned. The images were analyzed, considering morphotypes in the biofilm, their density, and spatial distribution. Results: No Vibrio was detected, but 5 different morphotypes were described and associated with possible genders (Lactobacillus, Porphyromonas, Actinomyces, Leptotrichia, Rothya, Neisseria, Staphylococcus, Veillonella, Peptostreptococcus, Streptococcus). Conclusion: Morphotypes are a good first approach to the main components of biofilm, results can be improved with better disaggregation techniques. Complementary genomics and proteomics techniques should be more conclusive.