Microbiology

The bacterial microbiome from dental biofilms can harbor more than 720 unique species. However, 800 to 1000 different oral bacterial taxa can be identified with the more modern techniques with differences in abundance and diversity patterns across age, sample quality and origin, and health status.¹⁴

Traditionally, Streptococcus mutans and Lactobacillus acidophilus have been the most studied bacterial species due to its virulent factors associated with caries development and progression. However, the latest evidence shows that, in addition to Streptococcus mutans, other bacteria are linked to the onset and progression of caries, including species such as Actinomyces and Bifidobacterium, Streptococcus salivarius, Streptococcus sobrinus, Streptococcus parasanguinis, Scardovia wiggsiae, Slackia exigua, Lactobacillus salivarius, Parascardovia denticolens, and various species of Porphyromonas and Veillonella.^15-19

This multi-specie cariogenic biofilm is usually made up of bacterial species that possess the following key characteristics: (1) the ability to adhere to the saliva-coated tooth surface, (2) the production of an exopolysaccharide (EPS)-rich matrix, which limits the spread of acidic by-products from carbohydrate fermentation, and (3) the ability to survive in an acidic environment. These traits ultimately lead to enamel dissolution due to the localized acidic microenvironments within the biofilm and at the tooth-biofilm interface.