Question

Native peoples often experience an increase in the incidence of dental caries after they are introduced to imported processed foods. This finding could be explained by the fact that __________.

Lactobacilli require sucrose in order to form biofilms on tooth surfaces.
Sucrose and other purified sugars cause pitting of the tooth surfaces.
Sucrose is required for the production of adhesive dextran by Streptococcus mutans.
Only purified sucrose and fructose can be fermented or produce acids in the oral cavity.

Answer 1

The increase in dental caries among native populations exposed to processed foods is due to the role of sucrose in enabling Streptococcus mutans to form a biofilm and produce acids through fermentation, leading to enamel erosion and cavities.

Step-by-step explanation:

Native populations may see an increase in dental caries after adopting processed foods because sucrose is essential for Streptococcus mutans to produce dextran, an adhesive component of dental plaque. The metabolism of sucrose by such bacteria leads to acid production, which erodes tooth enamel and results in cavities.

When S. mutans breaks down sucrose, it creates both dextran and organic acids through fermentation. Dextran forms part of the biofilm that firmly attaches the bacterial communities to the tooth surface, which then facilitates the action of acids on teeth. These acids demineralize the tooth enamel, contributing to the formation of caries. The acids are particularly damaging to exposed dentin. Regular dental care, including cleanings and reduction of sugar intake, helps prevent decay by disrupting microbial growth and biofilm accumulation.