Chapter 5.2: Oral Microbial Biofilms.

Bacteria, fungi, archaea, protozoa, viruses, and bacteriophages colonize the oral cavity and, in combination, they form the oral microbiome. The coexistence of different microorganisms and the microbial balance at each specific site are warranted by synergistic and antagonist interactions among members of the microbial communities. This microbiological balance suppresses the growth of potentially pathogenic microorganisms, generally keeping them at low abundance in the colonized sites. Microbial communities coexist in harmony with the host being compatible with a health condition. On the other hand, stressors exert selective pressure on the microbiota, promoting disruption in microbial homeostasis leading to dysbiosis. In this process, potentially pathogenic microorganisms become more abundant, resulting in microbial communities with altered properties and functions. Once the dysbiotic state has been reached, increased disease risk is expected. Biofilm is essential for caries development. The knowledge of the composition and metabolic interactions in the microbial community is fundamental for developing effective preventive and therapeutic measures. Studying both health and cariogenic conditions will bring an essential understanding of the disease process. Recent advances in omics approaches provide an unparalleled potential to reveal new insights about dental caries. This chapter will discuss a broader perspective on the etiology and pathogenesis of coronal dental caries from biofilm structure to microbial interactions.