Updated: Sep 28, 2019

Although biofilms can form on all wet surfaces of the body, this article will focus specifically on the dental version.

Biofilm was once more widely known and talked about as dental plaque. The more scientific term, ‘biofilm’ has taken its place because it more completely underlines the dynamic, living, adaptive quality of this disease-causing agent. Biofilms are important because they are increasingly implicated in the development of many of the chronic diseases we humans experience.

What is biofilm?

It is an organised, structured and cooperative community of many species of bacteria. These organisms live in a matrix of sticky and supportive molecules they produce specifically for the purpose of attaching themselves to our tissues.

Biofilm appears to the naked eye to be a cream coloured, slimy, disorganised, mass that grows along the gumline and between our teeth. It appears to be a random aggregation of 'stuff'.

Nothing could be further from the truth. The nature of this substance is extraordinary, a testament to the intelligence of nature and worthy of our respect - even though it has the potential to do great harm to our health.

Facts about biofilm.

  • Although biofilm lives on the surface of our body, it has great potential to harm the teeth through decay and soft tissues of the gums through gingivitis and periodontitis.

  • The matrix of the biofilm is an incredible material. It not only allows the biofilm to adhere firmly to the teeth and gums, it is structured in such a sophisticated way that nutrients are deliberately circulated into it, and toxic waste products are actively moved out.

  • Different species of bacteria gather in very specific clusters that are mutually beneficial – the waste products of some bacterial species provide perfect nutrition others, allowing all of them to thrive. It is likely that they offer each other benefits in ways we do not yet know.

  • The bacteria communicate with each other through the matrix to coordinate the way they express genes, for the benefit of the whole community. This phenomenon is called Quorum sensing.

  • The bacteria also share genes with each other, allowing them to pass on beneficial traits such as antibiotic resistance, improved ability to adhere to our tissues, and the ability to produce sticky matrix molecules.

  • The thicker a biofilm grows, the more diverse and nasty its members become. This is because a thick biofilm cleverly creates the optimal environment for pathogenic (disease causing bacteria) to thrive. One of the means by which this happens is that thick biofilm resists the ability of oxygen to penetrate its depths – some of the most vicious bacteria proliferate in low oxygen environments.


Biofilm is a living material that will grow continuously in our mouths when left unchecked. It's behaviour is a reminder that we cannot think of bacteria as unintelligent, uncommunicative loners, bouncing aimlessly around in our mouths, causing infection by accident.

Biofilm is a highly organised, collaborative, communal structure that lends great survival capacity to its bacterial members – far exceeding the strategies they are capable of on their own. Their co-operation allows the proliferation of bacteria that pose a significant risk to the health of our teeth, gums and whole body.


It is the biofilm, fuelled by sugar, that causes tooth decay.

It is the biofilm that causes gum disease.

It is the biofilm that contributes to heart disease, stroke, diabetes, poor pregnancy outcomes, lung disease and Alzheimer’s Disease through untreated gum infections.

What we need to know about biofilms.

  • The nature of biofilm makes it resistant to the lethal chemicals in mouthwash. Do not imagine that mouthwash can replace interproximal cleaning and/or tooth brushing. These chemicals ‘bounce’ off the surface of the biofilm and the disease-causing bacteria deep inside are completely untouched.

  • Antibiotics cannot treat biofilm. The bacteria in it are capable of developing antibiotic resistance through gene sharing. And the film is on the surface of the body where oral antibiotics cannot reach it. The only times antibiotics are of use is when the bacteria have left the biofilm and entered the tissues of the body, causing acute infection.

  • Your immune system should not be left to handle biofilm ‘on its own’. It cannot. The whole point of the biofilm is that it behaves like a highly trained military force – it is capable of defying the best our immune system can throw it. In fact, certain bacteria in the biofilm turn our immune system against itself and our body.

  • The formation of biofilm happens constantly. This is why consistent oral hygiene is the key. Brushing twice a day and flossing once per day keeps the biofilm thin and this prevents the nasty organisms from taking hold. When we are ‘on and off’ with our flossing (for example flossing once per week) the biofilm has the opportunity to become thick and destructive and we are always on the back foot with our efforts.

  • We create the characteristics and quality of our biofilm with our diet, our hygiene, our habits and most likely our entire lifestyle.

  • Sugar, and especially sucrose, provides one of the most essential building blocks for the formation of the matrix of the biofilm. It also creates the best conditions for decay-causing bacteria to thrive. Reduce sugar intake and these bacteria will struggle to make biofilm and survive in your mouth.

  • The only thing that breaks up the diabolically intelligent structure of biofilm is mechanical cleaning (brushing and interproximal cleaning). Toothpaste helps because the detergent grabs and binds the loose bacteria before they can settle back on the teeth and create a new biofilm.

  • Biofilm upsets the immune system in our gums. The result is inflammation with no possible end (if we do not intervene with good hygiene) because the biofilm provides a constant source of toxins and bacterial invaders.

  • The inflammation in turn makes the gum tissues ‘leaky’, allowing bacteria to enter the blood stream and cause a host of other diseases.

  • The biofilm cannot ever be eliminated, but it can be made harmless when we keep it very thin with good oral hygiene.

The fact is that while we remain ignorant to the intelligent co-ordination of our bacterial co-habitants, we have an enemy that can devastate us from the inside.

Yet the answers to the array of problems bacteria and their biofilm can causes are really so simple:

  • Consistent low sugar diet

  • Consistent interproximal tooth cleaning by whatever method works for you, and

  • Consistent, effective and attentive tooth brushing.

Note the key word, consistent.

Bacteria are consistent in their determination to thrive and reproduce. They do not lose interest, they never give up and they do not get distracted.

We human beings need to be equally consistent in our dedication to taking the steps that ensure our own wellbeing.

It is only then that the biofilm does not stand a chance.


Banthia, R., Chandki, R., & Banthia, P. (2011). Biofilms: A microbial home. Journal Of Indian Society Of Periodontology, 15(2), 111. doi: 10.4103/0972-124x.84377

Stalder T, Top E. Plasmid transfer in biofilms: a perspective on limitations and opportunities. NPJ Biofilms Microbiomes. 2016;2:16022–. doi:10.1038/npjbiofilms.2016.22

Hollmann, B., Perkins, M., & Walsh, D. (2019). Biofilms and their role in pathogenesis | British Society for Immunology. Retrieved 18 September 2019, from

Vidyasagar, A. (2019). What Are Biofilms?. Retrieved 18 September 2019, from

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