What does oral immunocompetence actually mean?

Perhaps you have come across the term oral immunocompetence before and are wondering what it actually means? A healthy oral immune system or immune fitness is of immense importance when it comes to your dental implants. But common diseases such as diabetes, heart disease, rheumatism and infertility are also reflected in your mouth. In this article, we take a closer look at this important connection and explain what it means for you and your health and how you can determine how fit your oral immune system is. Last but not least, a healthy oral immune system contributes significantly to the ingrowth of implants, their lifespan and few complications.

When is an immune system competent?

The tasks of the immune system are not that simple. It has to recognize intruders at exactly the right time and then unleash a whole cascade of defence mechanisms to render them harmless. It is no good if the immune system reacts too quickly and too violently, nor if it reacts too late and far too weakly. Timing and reaction strength are the determining factors in a healthy immune system.

If it reacts too violently, vast amounts of messenger substances (cytokines) are released, which can ultimately lead to damage to the organs (as in the case of sepsis). If it reacts too late, the germs may have already spread throughout the body and the immune system can no longer fight this overwhelming force on its own, then we intervene with antibiotics.

There are also countless forms of misdirected immune systems. In some cases, the immune system reacts violently to completely harmless substances - these are allergies, which can sometimes even be life-threatening. In other cases, the immune system is directed against the body's own substances or tissue - then we speak of autoimmune diseases.

Almost every second person suffers from inflammation in the mouth

You are aware that the immune system plays a role in colds. But why is the oral immune system so important and what is the connection to the rest of the body?

The oral cavity - together with the nasopharynx - is the entry point for almost all substances from our environment. Every time we eat, we ingest countless germs that first end up in our mouths. Many viruses, such as cold viruses and even coronaviruses, enter our bodies via the oral cavity. (1) So you can see how important it is that the immune system in the mouth (oral immune system) reacts just right.

With adequate hygiene and good general health, this is not a problem for the body. However, the WHO (World Health Organization) has determined that inflammation of the periodontium (periodontitis - which also includes inflammation of implants - peri-implantitis) is the most common infectious disease in humans and affects almost one in two people. However, most people have no idea what is happening in their mouths. (2) In Germany alone, an estimated 11.5 million people are affected. (3)

The oral immune system as a mirror of the body

But many people don't know this: Diseases of the body and diseases in the oral cavity are closely related. Unfortunately, far too many doctors and dentists still regard the oral cavity and the rest of the body as something independent. Close cooperation would have a positive effect on systemic (physical) and oral diseases at the same time.

Apparently, the immune system in the mouth is so sensitive that diseases such as diabetes, heart disease and rheumatism can be directly detected by the condition of the oral cavity. Conversely, inflammation of the oral cavity apparently prevents pregnancy - some women only became pregnant after having their oral cavity cleaned. However, rheumatoid arthritis and even Alzheimer's disease also appear to have a connection with the health of the oral cavity. (4)

1. diabetes and the oral immune system
Periodontitis and diabetes are both very common diseases that influence each other. Patients with diabetes not only have periodontitis more frequently, but also periodontitis with a higher degree of severity. The worse the blood sugar control, the worse the periodontitis. (5)
A recent Greek study found that 27.5% of all patients visiting the dentist had high blood sugar levels - without knowing it. A so-called aMMP-8 test, which was actually intended to test for periodontitis, had fished out precisely these people with high blood sugar. (6) A clear sign of how closely the two diseases are linked.
Diabetes, blood circulation and wound healing are a well-known topic. You have probably also heard of diabetic foot. The causes are poorer circulation, damage to the nerves and a weaker immune system. The tiny, highly perfused capillaries in your oral cavity naturally react much more sensitively to blood sugar and are something of an early warning system.

Therefore, anyone with diabetes should keep a particularly close eye on their oral immune status. But the reverse is also true: anyone who has recurring problems with periodontitis should have their blood sugar checked thoroughly.

2. diseases of the cardiovascular system and the oral immune system

However, it is not only patients with diabetes who suffer more frequently from periodontitis, but also patients with cardiovascular disease. Numerous studies have shown a link between chronic cardiovascular disease and periodontitis. (7) What both diseases have in common is that a silent inflammation is at work - you may have heard the term silent inflammation before. These inflammatory processes lead to tiny inflamed areas in the blood vessels, forming scar tissue to which further cells can eventually attach and close the vessel.

If the oral immune system is weakened by bad germs and inflammation, this affects the entire body. If the immune system is challenged by inflammatory reactions in the blood vessels, this is also reflected in the mouth. Both diseases are interrelated and the following also applies here: anyone with heart disease should pay particular attention to their oral cavity and anyone with periodontitis should not only have their blood sugar checked, but also their cardiological condition.

These two examples show how important it is for dentists and doctors to work closely together. This is because the condition of the oral immune system provides information about the condition of the entire body and, conversely, the diseases of the body are reflected in the oral cavity.

It is therefore particularly important to know how your oral immune system is doing before inserting implants in order to allow the implants to grow in without complications. And even existing implants are affected by inflammation on the implant after nine years in almost half of all cases. To prevent this, it is important to regularly check the condition of your oral cavity before deep pockets have formed or bone resorption becomes visible on x-rays.

How you can measure your oral immunocompetence

There is a large group of enzymes in our body that are involved in the formation and breakdown of tissue. These have the unwieldy name matrix metalloproteinases (MMPs for short). MMP-8 plays a special role here - it belongs to the group of collagenases. This means that this enzyme breaks down our collagen. Collagen is not only important for firm skin, but also plays a crucial role throughout the body as supporting and retaining tissue. The entire periodontium is supported by firm collagen fibers and ensures a tight seal of the gums around the tooth and keeps the teeth in place.

When it comes to harmful bacteria or inflammatory processes due to disease, white blood cells activate the enzyme MMP-8 to clear the way for phagocytes to reach the site of inflammation. This enzyme plays a key role in inflammatory processes and the resulting tissue breakdown. It is released so early that it can be measured long before visible damage to the periodontium or bone and is therefore an ideal early warning system.

A simple saliva test provides clarity

Finnish researchers and German biotechnology experts have succeeded in developing a test that can detect whether these destructive processes are taking place in your mouth from a saliva sample alone. The test determines the concentration of activated matrix metalloproteinase-8 (aMMP-8) and is not only used by dentists, but now also by interdisciplinary internists, diabetologists and cardiologists to determine the state of the oral immune system.

Unfortunately, the test is still a self-pay service (IGeL) and costs around 50€. There is a professional version for use in the medical field, which provides information about the exact amount of aMMP-8, but there is also a simple yes/no test for home use. This is as simple as a pregnancy test and tells you whether a critical amount of aMMP-8 has been exceeded.

Particularly interesting for implant wearers: with the professional version, a sample can be taken directly at the implant to check whether everything is in order there.

However, it is also advisable to determine the aMMP-8 before inserting an implant, as tooth loss often occurs due to periodontitis. Inflammatory reactions have taken place in the tissue and bone, resulting in the tooth no longer being fixed in place. However, this also means that bacteria were and are at work at this site, which must be completely eliminated before it is worth placing an implant at this site. Otherwise, problems with ingrowth and subsequent implant loss due to peri-implantitis are a risk that should not be underestimated. Anyone investing in an implant should definitely plan for the costs of a healthy oral immune system. Regular aMMP-8 measurements (twice a year), appropriate dental hygiene (three to six times a year - depending on the state of your oral health) and daily care with interdental brushes and dental floss will ensure that you can enjoy your implant for a long time without complications. Love your implant!



  1. High expression of ACE2 receptor of 2019-nCoV on the epithelial cells of oral mucosa. Xu, Hao & Zhong, Liang & Deng, Jiaxin & Peng, Jiakuan & Hongxia, Dan & Zeng, Xin & Li, Taiwen & Chen, Qianming. (2020). International Journal of Oral Science. 12
  2. Review: Strengthening the Prevention of Periodontal Disease: The WHO Approach. Poul Erik Petersen and Hiroshi Ogawa. J Periodontol (12/2005)
  3. Fünfte Deutsche Mundgesundheitsstudie (DMS V)https://www.bzaek.de/fileadmin/PDFs/dms/Zusammenfassung_DMS_V.pdf
  4. From focal sepsis to periodontal medicine: a century of exploring the role of the oral microbiome in systemic disease. Purnima S. Kumar. J Physiol 595.2 (2017) pp 465–476
  5. Diabetes and periodontal disease: a two-way relationship. L. Casanova, F. J. Hughes and P. M. Preshaw. British Dental Journal 2014; 217: 433-437. DOI: 10.1038/sj.bdj.2014.907
  6. Prediabetes/Diabetes Can Be Screened at the Dental Office by a Low-Cost and Fast Chair-Side/Point-of-Care aMMP-8 Immunotest; Andreas Grigoriadis, Timo Sorsa, Ismo Räisänen, Pirjo Pärnänen, Taina Tervahartiala, and Dimitra Sakellari; Diagnostics 2019, 9, 151; doi:10.3390/diagnostics9040151
  7. Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease. Hatem Alfakry, Ernst Malle, Chintan N Koyani, Pirkko J Pussinen, Timo Sorsa. Innate Immunity 2015; 22:1.https://doi.org/10.1177/1753425915617521