Plaque buildup on teeth is the root cause of teeth and gum-related diseases such as cavities, gingivitis and gum recession.
Plaque buildup on teeth is a structured, resilient, whitish yellow substance that clings tenaciously to the teeth and other structures and is composed of tiny food particles, bacteria, and waste products of bacteria.
Bacteria present in the mouth readily colonise exposed surfaces of the teeth within 4 to 10 hours after toothbrushing or flossing and form a thin sticky film called plaque or dental plaque.
Plaque buildup irritates gums and initiates gum inflammation (gingivitis). Howover, a long-standing presence of plaque leads to enamel demineralization (cavities) and gum recession (periodontitis). Based on the available evidence, current practices typically emphasise optimal plaque control for maintaining oral health.
Plaque control maintains your teeth in good health and function while preventing the onset and progression of dental and gum diseases.
Can you see a plaque on your teeth?
Plaque buildup is hard to detect on teeth because it has the same colour as your teeth.
As mentioned earlier, plaque starts to accumulate within 4-10 hours after brushing. If you wipe your tongue over the teeth 24 hours after brushing you may feel roughness or a layer deposited on the teeth instead of a smooth clean surface.
A dental floss shows white deposits when removed in between the teeth.
If you have plaque deposits in your mouth you may also experience bad breath and/or bleeding gums on brushing.
How does plaque form on teeth?
Bacteria rarely come into contact with a clean tooth surface. As soon as a tooth has been cleaned, salivary and bacterial molecules gather or precipitate on the enamel surface and form an initial film called a pellicle.
This film is usually < 1 micrometre thick, and it takes 90-120 min for the precipitated molecules to reach their maximum level.
The pellicle contains proteins, enzymes and antibodies precipitated from saliva, as well as enzymes (glucosyltransferases) and glucans from bacteria.
These precipitated molecules provide adhesion for bacteria, and therefore selectively influence the pattern of plaque buildup.
Relatively few oral bacteria are motile and are generally transported passively to the tooth surface by the force of saliva flow.
As bacteria approach pellicle-coated enamel, they lie at around 10-20 nm from the surface. The strength of this attraction or adhesion is relatively weak, and this phase of attachment is reversible.
Attachment of bacterial to tooth surface
The strength of attachment to the tooth surface can increase if the bacteria get closer to the surface. For this to happen, water film from saliva must be removed between the interacting tooth and bacteria.
Some bacteria bear some fibrous attachments on their surface that aids bacteria to attach directly to the tooth surface while others adhere to teeth by binding to the precipitated salivary proteins such as proline-rich salivary proteins.
The bacteria in the plaque also tend to bind to other bacteria, further diversifying the composition of bacterial plaque and the process is known as co-aggregation.
production of extracellular polysaccharides by bacteria
Adherent bacteria also produce high molecular weight sugar-based polymers called extracellular polysaccharides (EPS) and influence plaque buildup.
The polysaccharide component of the plaque matrix provides many diverse functions to the cells in the plaque, including sticking, protection, and structure. These polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as to the tooth surfaces.
EPS, however, may lead to an increased challenge to tooth decay at the tooth surface because, in a thick plaque, EPS enables sugars to penetrate deeper into the biofilm, while the significant buffering effect of saliva will be reduced, thereby producing a more pronounced pH fall at the plaque-enamel interface.
Who gets plaque more frequently?
Everyone gets the plaque but the tendency to plaque buildup increases if you have the following conditions:
- Crooked or crowded teeth – crowded or irregularly aligned teeth make brushing and flossing more difficult than straight and normally aligned teeth.
- Dry mouth – low salivary flow favour plaque buildup because saliva washes away bacteria and food particles from the mouth.
- Head and neck radiations – affects the functioning of salivary glands and thus allow more plaque buildup on teeth.
- Medication that causes dryness of mouth – are also linked to more plaque accumulation.
Plaque is a sticky film attached to the tooth surface a few hours after brushing. Plaque is important because it is the cause of gums and teeth-related diseases and adequate plaque control can stop the initiation and progression of these diseases.