Australian Dental Council (ADC) Test 2026 – 400 Free Practice Questions to Pass the Exam

Streptococcus mutans predominantly utilizes sucrose to form dextran. Sucrose, a disaccharide sugar composed of glucose and fructose, serves as a substrate for these bacteria. When S. mutans metabolizes sucrose, it produces an enzyme called glucosyltransferase, which facilitates the conversion of the glucose component of sucrose into dextran, a polysaccharide. This dextran serves as a vital component in the biofilm that adheres to tooth surfaces, contributing to plaque formation and ultimately dental caries.

The ability of S. mutans to utilize sucrose in this way highlights the role of dietary sugars in dental health and the pathogenic processes leading to tooth decay. While glucose can also be fermented by these bacteria, it does not contribute to dextran synthesis in the same manner as sucrose. Fructose, while a product of sucrose breakdown, does not lead to the formation of dextran. Amylopectin, a starch component, is not a direct substrate for dextran synthesis by S. mutans. Understanding the specific carbohydrates that S. mutans utilizes is crucial for reinforcing the importance of dietary choices in oral health contexts.