Dental biofilm, commonly known as dental plaque, is a community of microorganisms, primarily bacteria, that attach to surfaces. In the mouth, this sticky, colorless film naturally accumulates on tooth surfaces, gums, and even dental restorations. While some bacteria in the mouth are beneficial, an imbalance or overgrowth of certain types within the biofilm can lead to oral health issues.
The Formation of Dental Biofilm
The formation of dental biofilm begins almost immediately after teeth are cleaned. Initially, a thin, invisible layer from saliva, known as the acquired pellicle, coats the tooth surface. This film provides a surface for microorganisms to adhere to.
Bacteria in the mouth, such as Streptococcus species, attach to this pellicle and begin to multiply. As these early colonizers grow, they attract other bacterial species, including more harmful types like Fusobacterium and Porphyromonas.
The bacteria within this developing community produce an extracellular polymeric substance (EPS), a protective slime layer. This matrix helps the bacteria adhere more strongly to the tooth surface and to each other. The biofilm continues to mature, becoming more resistant to external disruption as new microorganisms join and consume available nutrients, such as sugars from food.
Health Consequences of Unmanaged Biofilm
When dental biofilm is not regularly removed, it can lead to various oral health problems. The bacteria within the biofilm consume sugars and starches from food, producing acids. These acids demineralize tooth enamel, the hard outer layer, which can result in tooth decay, also known as cavities.
Biofilm accumulation at the gumline can trigger an immune response, leading to inflammation of the gums, a condition called gingivitis. Symptoms include redness, swelling, and bleeding, particularly during brushing or flossing. This is the earliest stage of gum disease and can often be reversed with diligent oral hygiene.
If dental biofilm remains undisturbed, it can absorb minerals from saliva and harden into a calcified deposit called calculus, or tartar. Unlike soft biofilm, tartar bonds strongly to the enamel and cannot be removed by brushing or flossing at home. Tartar provides a rough surface that encourages further biofilm accumulation, increasing the risk of more severe gum disease, such as periodontitis, which can damage the bone supporting the teeth.
Controlling and Preventing Biofilm
Managing and preventing harmful dental biofilm buildup primarily relies on mechanical disruption. Brushing teeth thoroughly for at least two minutes, twice a day, is effective in dislodging bacteria from tooth surfaces. Using a soft-bristled toothbrush and fluoride toothpaste helps to clean all accessible areas, including around the gumline.
Daily flossing or using interdental cleaners is also important to remove biofilm and food particles from between teeth and beneath the gumline, areas a toothbrush cannot easily reach. Disrupting biofilm through these methods is the most direct way to prevent its maturation and associated health problems. While mouthwash can help reduce bacteria, it is not a substitute for mechanical cleaning.
Dietary choices also influence biofilm activity; reducing the intake of sugary and starchy foods limits the “fuel” available for acid-producing bacteria. Drinking plenty of water can help rinse away food debris and neutralize acids in the mouth, supporting a healthier oral environment. Regular professional dental cleanings are also necessary to remove any biofilm missed by home care and to remove hardened calculus that cannot be removed at home.