Which substance produced by Streptococcus mutans contributes to the dental plaque matrix?

Which substance produced by Streptococcus mutans contributes to the dental plaque matrix?

• A. Lactic acid
• B. Sucrose
• C. Glucose
• D. Dextran

Answer: (D)

Streptococcus mutans helps form the dental plaque matrix by making extracellular polysaccharides that glue cells to each other and to the tooth surface. The key substance is dextran, a glucan produced from sucrose by bacterial glucosyltransferase enzymes. This dextran becomes part of the sticky plaque matrix, facilitating adherence and biofilm structure on enamel. While lactic acid is produced from sugar fermentation and contributes to tooth decay, and sucrose serves as the substrate for making the matrix, the polymer that actually builds the plaque’s sticky matrix is dextran.

Streptococcus mutans helps form the dental plaque matrix by making extracellular polysaccharides that glue cells to each other and to the tooth surface. The key substance is dextran, a glucan produced from sucrose by bacterial glucosyltransferase enzymes. This dextran becomes part of the sticky plaque matrix, facilitating adherence and biofilm structure on enamel. While lactic acid is produced from sugar fermentation and contributes to tooth decay, and sucrose serves as the substrate for making the matrix, the polymer that actually builds the plaque’s sticky matrix is dextran.