Some salivary components are crucial for plaques ecosystem, such as salivary alpha-amylase which plays a role in binding and adhesion. Proline-rich proteins (PRP) and statherins are also involved in the formation of plaque. Supragingival biofilm
Supragingival biofilm is dental plaque that forms above the gums, and is the first kind of plaque to form after the brushing of the teeth. It commonly forms in between the teeth, in the pits and grooves of the teeth and along the gums. It is made up of mostly aerobic bacteria, meaning these bacteria need oxygen to survive. If plaque remains on the tooth for a longer period of time, anaerobic bacteria begin to grow in this plaque. Subgingival biofilm
Subgingival biofilm is plaque that is located under the gums. It occurs after the formation of the supragingival biofilm by a downward growth of the bacteria from above the gums to below. This plaque is mostly made up of anaerobic bacteria, meaning that these bacteria will only survive if there is no oxygen. As this plaque attaches in a pocket under the gums, they are not exposed to oxygen in the mouth and will therefore thrive if not removed.The extracellular matrix contains proteins, long-chain polysaccharides and lipids. The most common reasons for ecosystem disruption are the ecological factors discussed in the environment section. The bacteria that exhibit the most fit plasticity for the change in environment dominate the given environment. Often, this leads to opportunistic pathogens which may cause dental caries and periodontal disease.
Understanding the formation, composition and characteristics of plaque helps in its control. An acquired pellicle is a layer of saliva that is composed of mainly glycoproteins and forms shortly after cleaning of the teeth or exposure of new teeth. Bacteria then attach to the pellicle layer, form micro-colonies, and mature on the tooth, which can result in oral diseases. The following table provides a more detailed (six-step) explanation of biofilm formation:

Components of plaque
Different types of bacteria are normally present in the mouth. These bacteria, as well as leukocytes, neutrophils, macrophages, and lymphocytes, are part of the normal oral cavity and contribute to the individuals health. Approximately 80–90% of the weight of plaque is water. While 70% of the dry weight is bacteria, the remaining 30% consists of polysaccharides and glycoproteins. Bacteria
The bulk of the microorganisms that form the biofilm are Streptococcus mutans and other anaerobes, though the precise composition varies by location in the mouth. Examples of such anaerobes include fusobacterium and actinobacteria. S. mutans and other anaerobes are the initial colonisers of the tooth surface, and play a major role in the establishment of the early biofilm community. Streptococcus mutans uses the enzyme glucansucrase to convert sucrose into a sticky, extracellular, dextran-based polysaccharide that allows the bacteria to cohere, forming plaque. (Sucrose is the only sugar that bacteria can use to form this sticky polysaccharide). These microorganisms all occur naturally in the oral cavity and are normally harmless.