What type of bacteria is present when plaque is first formed?

When plaque is first formed on the surface of teeth, it is primarily composed of gram-positive aerobes. These bacteria are typically among the initial colonizers following the accumulation of a film of salivary glycoproteins on the enamel surface. The early plaque-forming bacteria thrive in an aerobic environment, using oxygen to metabolize sugars and other nutrients.

These gram-positive aerobes, including species such as Streptococcus mitis and Streptococcus sanguinis, play a crucial role in the development of dental biofilms. They begin the process of biofilm maturation by adhering to the tooth surface, and as plaque accumulates, it creates an environment that can support the growth of additional bacteria, including gram-negative anaerobes, which are more commonly found in later stages of plaque formation. Understanding the role of these early colonizers is essential for grasping how plaque develops and eventually leads to dental issues, such as caries and periodontal disease.