Everything You Need to Know About Dental Bacterial Plaque

Being attentive and controlling dental plaque is a way to take care of our oral health. We'll tell you everything you need to know about it.
Everything You Need to Know About Dental Bacterial Plaque
Vanesa Evangelina Buffa

Written and verified by the dentist Vanesa Evangelina Buffa.

Last update: 26 October, 2022

The origin of many oral problems is what is known as dental bacterial plaque. This is the sticky film that adheres to tooth surfaces and that we try to remove with oral hygiene.

Dental plaque is made up of bacteria and sugars and is constantly forming. That’s why it must be removed over and over again, several times a day, every day.

If we neglect this, plaque becomes a threat to oral health. Cavities, periodontal disease, bad breath, and teeth that look dirty and stained are some of the possible consequences.

Knowing how dental plaque is formed will help you control it and prevent the problems it causes. We’ll tell you in more detail about this process that takes place in the mouth.

What is dental bacterial plaque?

As we’ve already mentioned, dental bacterial plaque is a viscous film that forms on the teeth every day. It arises from the combination of microorganisms in the mouth with saliva and food debris.

Scientists prefer to call it a “biofilm” because it’s actually a community of different living microorganisms surrounded by a layer of sticky polymers that form a complex ecological unit. This glutinous layer allows microbes to adhere to the surfaces of the mouth and form thriving microcolonies.

The oral cavity is colonized by many different microorganisms that are part of the flora of the gastrointestinal tract. These germs present in the mouth are usually kept in equilibrium. But, when some strains develop in excess, problems arise.

Some bacteria are aerobic, i.e. they develop in the presence of air; others, on the contrary, are anaerobic. They can also be differentiated according to the way they react to a Gram-positive and Gram-negative stain. The diseases they can give rise to depend on these characteristics.

Dental bacterial plaque forms constantly, during the night when sleeping and during the day after eating and drinking. It’s most commonly found on tooth surfaces, along the gum line, and on the tongue.

Dental bacterial plaque is transparent or a dull yellowish-white color. When formed, its consistency is soft, but if it isn’t removed, over time it calcifies, giving rise to what’s known as tartar or calculus.

A person with plaque.
Dental tartar is the evolution of plaque, which hardens and takes on a darker color.

Types of dental bacterial plaque

Dental bacterial plaque is composed of many microorganisms of different species. Depending on the type of bacteria that predominate, there will be different consequences that this film can cause on teeth or gums.

Thus we can distinguish the following types of plaque according to the germs:

  • Kariogenic: This is mainly formed by the bacteria that cause caries. These microorganisms metabolize dietary sugars and produce lactic acid, capable of destroying the hard tissues of the teeth. Streptococcus mutans is the most prominent agent in this type of plaque.
  • Periodontopathogenic: In this case, the dominant bacteria are capable of causing gingivitis and periodontal disease. These germs, when metabolizing sugars, originate basic substances that attack the periodontium, causing its inflammation and destruction.
  • Harmless: It has very few bacteria, so it’s considered not capable of damaging the teeth and periodontium.

Another classification of dental bacterial plaque is according to the place in the mouth where it accumulates. We can distinguish the following types:

  • Supragingival: This is the bacterial plaque that accumulates above the gums, on the teeth. It can be made up of both cariogenic and periodontopathogenic bacteria, although the former are usually more common.
  • Subgingival: In this case, the plaque is located below the gums, inside the gingival sulcus and in the periodontal pockets. It’s usually periodontopathogenic bacteria.

How is dental bacterial plaque formed?

The mouth contains many types of germs that are kept in balance, and form a real oral ecosystem. The combination of these microorganisms with the characteristics of the mouth leads to the formation of dental bacterial plaque.

The process begins with the deposition of salivary proteins and crevicular fluid on the tooth surfaces. This first acellular film contains carboxyls and sulfates that increase the negative charge of the enamel.

Microorganisms residing in the oral cavity approach this layer and then adhere to it. The germs colonize the protein film and the first bacterial colonies begin to develop.

These bacterial colonies continue to grow through the aggregation and co-aggregation of more germs and their metabolic products. If the bacterial plaque formed isn’t removed, this process of proliferation and accumulation continues. The complexity of the flora increases and inorganic salts also begin to be deposited, transforming the plaque into calculus or tartar.

Therefore, the process of dental bacterial plaque formation can be considered a normal mechanism of the oral cavity. The problem arises when this film isn’t removed frequently and bacterial proliferation increases. Also, when other external factors, such as a sweet diet, favor the development of pathogenic germs.


When dental bacterial plaque is new, its appearance is colorless and it’s difficult to see with the naked eye. But if it isn’t removed, with the passage of time it acquires a greater thickness and a darker coloration that makes it detectable.

In the dental clinic, the dentist will use a small mirror and an explorer or probe to observe and detect bacterial plaque in the mouth. The probe has a fine tip that allows the dentist to rub the tooth surfaces and remove the accumulated film, revealing its presence.

In addition, to better observe the bacterial plaque, there are chemical products that stain it, allowing it to be seen in a color that’s easier to detect. These are the bacterial plaque developers.

These products allow the patient to clearly observe the places where bacteria accumulate the most. In this way, more emphasis can be placed on cleaning the area. It also helps dentists differentiate between old and new plaque.

Plaque disclosers come in tablets to be sucked or as liquids for rinsing. They’re simple to use and, once plaque is detected, the stain is removed with proper tooth brushing.

With the information obtained, the dentist can make a plaque index of the patient. This allows clarifying the oral cleanliness conditions and any risks involved, thus guiding the future preventive and therapeutic measures to be used.


Dental bacterial plaque that accumulates on teeth and gums and which isn’t removed with proper hygiene can give rise to various problems in the mouth. Cavities, gingivitis, periodontal disease, oral infections, and bad breath are the most common.

Therefore, to prevent these problems and control the formation of this potentially harmful film, it’s necessary to remove it on a regular basis. The treatment against bacterial plaque is oral hygiene.

This is carried out by the patient at home, with proper tooth brushing, flossing, and mouth rinses. Professional cleaning is also appropriate. The dentist can reach all areas of the mouth and remove all traces of plaque that the person fails to remove.

Cleaning treatments are also necessary in cases where the plaque has calcified and transformed into tartar. Calculus can’t be removed by brushing. The dentist, depending on the severity of the case, will remove these hard deposits with the most appropriate techniqu.

How to prevent dental bacterial plaque

To prevent dental bacterial plaque from becoming a health problem, it’s essential to keep it under control. Here’s how you can reduce its formation and prevent its accumulation.

Practice proper oral hygiene

The best way to prevent dental plaque from building up is to remove it every day. The bristles of the toothbrush are able to dislodge and sweep away the film adhered on the teeth. Therefore, it’s advisable to brush your teeth after every meal.

Brushing should reach the gums and all tooth surfaces of all the elements present in the mouth. And it should last at least 2 minutes.

In addition, it’s also necessary to sanitize the tongue. A tongue scraper will be of great help to keep it free of debris.

Flossing is also very important. Flossing between the teeth removes dental bacterial plaque from the interproximal area, where brushing cannot reach. Interdental brushes and irrigators are complementary accessories that can make cleaning these areas easier.

Fluoride toothpastes are an excellent complement to oral care. This mineral helps prevent cavities and prevents the growth of harmful bacteria.

Mouth rinses are another way to keep oral bacteria under control. Mouth rinses allow you to reach areas of the mouth where other methods cannot.

Mouth rinses can be composed of different active ingredients that reduce the multiplication of germs. Chlorhexidine (CHX), probiotics, herbs and essential oils are some of them. The dentist will be able to recommend the best option for each particular case.

A woman rinsing her mouth.
A mouthwash with a suitable product can complement brushing and flossing to reduce plaque.

Look after your diet

In addition to proper oral hygiene, taking care of the food we eat helps us control germs in the mouth. Eat a healthy diet and avoid foods that are rich in sugar, ultra-processed foods, and simple carbohydrates, especially those with a sticky consistency.

Avoid sweets, industrial pastries, and soft drinks in order to reduce the multiplication of bacteria. Since they don’t have nutrients that are easy to metabolize, it will be more difficult to remove them.

Using sugar-free chewing gum or chewing gum with xylitol is a good way to stimulate salivary production. This increases the self-cleaning of the mouth, reducing the bacterial plaque that accumulates throughout the day.

According to the American Dental Association (ADA), chewing sugarless gum for 20 minutes after meals helps prevent cavities.

Visit the dentist regularly

Visiting the dentist every six months, or at least once a year, is another way to keep control of dental plaque in your mouth. The professional will be able to detect any problems that arise and treat them in time.

In addition, as we already told you, with professional cleanings the dentist will perform a deep oral hygiene. It reaches all the hard-to-reach places and removes tartar that has formed and accumulated.

Pay attention to dental bacterial plaque

The formation of dental bacterial plaque is something that occurs in everyone’s mouth. Various strains of germs adhere to the teeth every day and night, forming this sticky layer.

Oral health depends on how we deal with this process. If we don’t intervene and let it accumulate, plaque turns into tartar, and increases the risk of caries, pyorrhea, and bad breath.

On the contrary, with careful brushing, flossing, mouthwashes, a healthy diet and biannual visits to the dentist it’s possible to control it. By paying attention and taking care of dental bacterial plaque with awareness, it’s possible to reduce its growth and maintain oral health.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

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This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.