What is established by age 2-3 and remains relatively stable, including cariogenic organisms, once established?

• A. Oral flora
• B. Saliva
• C. Enamel
• D. Plaque

Answer: (A)

The main idea is that the mouth’s microbial community becomes established early in life and then remains relatively stable, with cariogenic organisms becoming a persistent part of that ecosystem. By about two to three years of age, the oral flora shows a mature-like composition, including acid-producing bacteria that contribute to caries risk, and this community tends to stay fairly constant unless disrupted. This is why the presence of cariogenic organisms is described as part of the established oral flora once the microbiome has settled. Saliva and enamel aren’t microbial communities—saliva is a fluid, and enamel is the tooth surface—while plaque is the Biofilm where microbes live, but the concept here refers to the broader, stable microbial ecosystem of the mouth.