Establishment of microcosm biofilm models that reproduce a cariogenic diet intake

Abstract

Biofilms were developed from human saliva on bovine enamel discs in four experimental conditions to investigate dental caries development: feast and famine (M1), abundance and scarcity (M2), three meals daily (M3), and three meals plus two snacks daily (M4). The main difference between these models was the diet for microbial growth. The evaluations included verifying the pH of the spent culture media and analyzing the enamel discs for demineralization (microhardness and roughness) and biofilms (biomass, viable populations of mutans streptococci, and total microbiota). Two major behaviors were observed: M1 and M2 promoted an acidic environment, while M3 and M4 maintained pH values closer to neutral. The demineralization process was slower in the neutral groups but more pronounced in M3, while a greater increase in microbiota and biomass was observed over time for both neutral groups. Thus, the M3 model was better at mimicking the oral environment that leads to demineralization.

Keywords:

• Dental caries
• tooth demineralization
• biofilms
• mutans streptococci
• saliva

Acknowledgments

The present research will be part of the PhD thesis by EJFS. This research was supported by the research overhead of a scholarship from the São Paulo Research Foundation (FAPESP #2017/26623-5 to EJFS). The authors thank the Coordination of Superior Level Staff Improvement (CAPES—Finance Code 001) for providing a scholarship to EJ.S (for two months) and the National Council for Scientific and Technological Development (CNPq) for providing a scholarship to RMD (#PIBIC47053). Also, the authors are grateful to the Laboratory of Structural Characterization (LCE/DEMa/UFSCar), Laboratory of Experimental Pathology and Biomaterials (at Unesp, School of Dentistry, Araraquara), and the Center for Radiation Technology-CTR IPEN/CNEN-SP, Brazil, for access to their facilities. In addition, the Colombian Institute of Educational Credit and Technical Studies Abroad provided funding for travel tickets and support to EJFS (ICETEX, credit ID 3594721).

Disclosure statement

The authors declare that they have no conflict of interest.

Ethical statement

This study was approved by the Ethics Committee on Animal Research (CEUA: no 03/2018) and Human Ethics Committee (CAAE: 82750117.6.0000.5416) of Unesp, School of Dentistry, Araraquara. All human subjects gave written informed consent in accordance with the Declaration of Helsinki.

Additional information

Funding

This research was supported by the research overhead and a scholarship from the São Paulo Research Foundation (FAPESP #2017/26623-5 to EJFS). Additional financial support was provided by the Coordination of Superior Level Staff Improvement (CAPES—Finance Code 001; scholarship to EJFS for two months) and the National Council for Scientific and Technological Development (CNPq #PIBIC47053; scholarship to RMD).