The extracellular matrix is a critical component of microbial biofilms, such as
dental plaque, maintaining the spatial arrangement of cells and coordinating cellular functions throughout the structure. The extracellular polymeric substances that comprise the matrix include
carbohydrates,
nucleic acids,
proteins, and
lipids, which are frequently organized into
macromolecular complexes and/or are associated with the surfaces of microbial cells within the biofilm. Cariogenic
dental plaque is rich in
glucan and
fructan polysaccharides derived from extracellular microbial metabolism of
dietary sucrose. By contrast, the matrix of subgingival
dental plaque is a
complex mixture of macromolecules that is still not well understood. Components of the matrix escape from microbial cells during lysis by active secretion or through the shedding of vesicles and serve to anchor microbial cells to the tooth surface. By maintaining the biofilm in close association with host tissues, the matrix facilitates interactions between microorganisms and the host. The outcome of these interactions may be the maintenance of health or the development of
dental disease, such as caries or
periodontitis. The matrix affords microbial cells protection against chemical and physical insults and hinders the eradication of pathogenic
dental plaque. Therefore, strategies to control the matrix are critical to maintain oral health. This review discusses recent advances in our understanding of the composition, origins, and function of the
dental plaque matrix, with a focus on subgingival
dental plaque. New strategies to control subgingival
dental plaque based on targeting the biofilm matrix are also considered.