The American Dental Association calls biofilms "microscopic communities". This may not sound too bad until you realize that these communities consist of naturally occurring water bacteria and fungi.
These communities are ambitious, extending thin layers over every surface they can reach.
The American Dental Hygienists' Association describes biofilm as "a complex, communal, 3-dimensional arrangement of bacteria".
Dental plaque biofilm is a major concern for dental health practitioners.
Biofilms are not only found on the teeth and gums. They are just about everywhere.
They make themselves at home in many locations on the human body. They show up on the external surfaces of the eye, on the surfaces of the teeth, on the tongue, and throughout the oral cavity.
They can cause infections and are linked with prostatitis, osteomyelitits, and with pneumonia in cystic fibrosis patients. Biofilm can appear as supragingival and subgingival plaque, which play a role in the formation of dental cavities and the emergence of periodontal diseases.
A biofilm offers protection to bacteria, as its slimy extracellular matrix covers the microbial community. Antibiotics, antiseptics and chemotherapeutic agents are limited in their abilities to penetrate the matrix and eliminate the bacteria.
Saliva and gingival creviular fluid will not flush the bacteria away. Only antiseptics that are specifically made to penetrate the plaque matrix can attack the bacteria.
Biofilm grows and develops in four stages. These stages are initial adherence, lag phase, rapid growth, and steady state.
Initial adherence binds bacteria to the surface of a tooth. Salivary components called acquired pellicle, is deposited on surfaces of the teeth. Between the pellicle, as well as proteins and peptides from the salivary glands, biofilm is able to form more easily.
Lag phase involves changes in genetic expression, also called phenotypic shifts. Bacterial growth lags.
Rapid growth manufactures an exopolysaccharide biofilm matrix. Microcolonies grow. Over time, more kinds of bacteria stick to the early colonies.