Why is it that some people with good dental habits still seem predisposed to dental disease, particularly periodontal disease? For this group of people, no matter how diligent their oral hygiene regime, they nonetheless develop gingivitis and periodontitis, often resulting in loss of vital oral structures such as gum tissue and bone. Three decades of growth in our understanding of microbiology and genetics have provided some clues to this mystery.
More recent research in microbiology has discovered that very specific, harmful microorganisms are always present in periodontal disease and that certain people are predisposed to harbouring these organisms in their mouths. Poor oral hygiene habits will further exacerbate the situation, but even diligent habits are not a guarantee that disease will not occur.
What bugs your mouth
The term "plaque" is now referred to as "biofilm." Biofilm is the aggregation of many types of microorganisms that form a colony on a solid surface where there is a continuous supply of fluid such as water or saliva. This accumulation of bacteria works together as a community, using fluid as a means of transmission.
There are close to 600 different species of bacteria that typically live in the mouth, most of which are considered friendly and innocuous. Some of these microorganisms, however, have been identified as extremely harmful. This is coupled with the fact that it only takes five hours for microorganisms in the mouth to double in number if left undisturbed. As they increase in number, they quickly create an intricate network of channels and protective layers that can produce specific proteins and enzymes in a process called quorum sensing.
In the bacterial world, quorum sensing is a complicated decision-making process whereby localized bacteria coordinate behaviour and regulate numerous processes such as secreting specific enzymes that have the ability to turn on and off the genes of other bacteria.
Immune system response--inflammation is key
Bacteria, yeast, fungi, protozoa and spirochetes have been identified in periodontal disease. A healthy mouth does not usually harbour protozoa or spirochetes.
These harmful microorganisms present in the oral cavity provoke the immune system directly and indirectly, which results in bone and tissue loss around the teeth.
How does this happen? To defend against this bacterial onslaught, the immune system sends in its troops in the form of white blood cells to kill the invaders in the area of inflammation (around the tooth). With their higher intelligence, the bacteria have the ability to confuse the defending white blood cells chemotactically (influenced by certain chemicals), among other ways, thereby incapacitating them.
The white blood cell has only a three-day life cycle. If it does not engulf and destroy a bacterium within that time it breaks apart and dies. But the white blood cell's enzymes are now available to attack the very tissue they were meant to protect. In the mouth, this could translate into deep periodontal pockets surrounding teeth due to the destruction of bone.
The body also responds to inflammation by delivering collagenase to open more pathways for the capillaries to send in more troops to the area. However, collagenase also causes degradation of the collagen, a prominent protein found in almost all dental tissue, such as the periodontal ligament that attaches the teeth to their bony sockets.
If this immune response continues over a prolonged period, serious damage ensues, leading to severe periodontal destruction.
Worse, for those patients with one or more failed root canals, microorganisms actually thrive in the area due to lack of circulation and drainage caused by the inflammation around the biofilm.
Another complication is when patients have mixed metals in the mouth. Gold crowns, mercury fillings, porcelain fused to metal prosthetics and even some composite restorations existing in the same mouth can result in heavy metal toxicity. Heavy metals reduce the ability of the immune system to resist harmful bacteria, protozoa and fungi. For example, if left unchecked, the fungi C.albicans and S.cerevisae can transform mercury to methyl mercury, which can cause damage to the nervous, cardiovascular and urinary systems, to name a few. Ninety-five percent of this methyl mercury is excreted back into the gut, creating a vicious, complicated cycle.
Connections to the body
Since all body cavities and systems (such as respiratory and digestive systems) are interconnected, the implications of having pathogenic organisms in the mouth extend well beyond the oral cavity.
The biofilm, especially the destructive microorganisms, can travel throughout the body cavities and barriers. Depending on individual situations such as genetic predispositions, these pathogens can wreak havoc on many of the body's systems and organs. In time they can create failure in cardiovascular, digestive, urinary, reproductive, respiratory and musculoskeletal systems.
The following are a few of the direct correlations I've observed over the past 35 years that highlight the oral health-systemic disease connection.
Sinus infections.
Dental pathologies such as failed root canals and periodontal disease involving the upper teeth provide the pathogenic bacteria, spirochetes, protozoa and other harmful invaders easy access to the sinus cavities, thus creating inflammation and disease of the sinuses.
There are 37 million sinus infections in the US every year. Most cases are treated with antibiotics, which often make the pathogens even stronger. Chronically infected root-canalled teeth can provide a constant supply of harmful organisms being transported from the mouth to the sinuses. Wherever scars or caverns (cavitations) exist in the body, such as with root-canalled teeth, the circulatory and lymphatic systems become disrupted and disabled, thereby protecting the pathogens from the immune system.
Neurological disorders.
As mentioned earlier, for patients with mixed metal restorations, the moist oral cavity facilitates a chemical reaction that releases toxic metals such as mercury, nickel and others, increasing the damaging effects of the harmful bacteria. When organic mercury is converted to methyl mercury in the presence of yeast in the mouth, this neurotoxic metal can cross the blood-brain barrier from the oral cavity, resulting in such catastrophic effects as neurological disorders.
Cardiovascular disease. Mounting evidence indicates that people who have periodontal disease also have a much higher chance of developing cardiovascular disease, such as atherosclerosis, coronary heart disease and stroke, than those individuals who take preventive measures to eliminate the biofilm in their mouths.
Biofilm harbours harmful bacteria that, during the inflammatory response, enter the bloodstream and can travel to other parts of the body, such as the heart. Chronic infections involving root-canalled teeth can also have an inflammatory response and a negative effect on major organs like the heart.
Ear infections. The loss of height of the dental bite in children and adults creates structural changes in the Eustachian tube that inhibits proper drainage in the ear canals. This in turn creates festering and increased virility of the microorganisms that cause middle ear infections. Over the years we have witnessed the resolution of many middle ear infections in children by simply raising their dental bite using a technique called "primary molar buildups."
In short, periodontal disease has been linked to many systemic and autoimmune diseases. The good news is that if we are able to influence the microflora early enough and keep the pathogens in check the body begins to rebuild itself.
Types of testing
Modern periodontal assessment tests can be used to identify several known harmful pathogens involved in gingivitis and periodontitis. These tests range from simple in-office tests to more sophisticated methods that require us to send samples to a laboratory.
The Bana test is a simple in-office test that can identify one or more of the pathogenic bacteria by testing for the enzymes that are produced by them. It is quick and reasonably priced. If the results indicate the presence of pathogens, we can take steps to reduce or eliminate their harmful effects using treatment options discussed below.
DNA testing for pathogens is a more sophisticated laboratory test that can identify the genetic markers for pathogens.
Another genotype test analyzes if a person carries the "turn on" inflammatory gene that produces interleukin or the anti-inflammatory expression. A person carrying the inflammatory gene would obviously be more prone to inflammation. For example, a person who smokes and carries the gene would have a much greater risk for developing periodontal disease.
A culture test is sent to a laboratory for specific identification of multiple species of microorganisms.
Microscopy can be used to reveal the presence of spirochetes and protozoa.
The results of the above tests give us information that was not available to us early on in our careers as dentists in regards to preventing, diagnosing and treating periodontal disease. This information is significant, and we are not only talking about periodontal disease anymore.
Treatment options
It is crucial to recognize unresolved periodontal infections, take steps to identify the pathogens involved and implement a protocol to control the destructive patterns of these organisms in the mouth.
There are many treatment options available once test results are in.
1. Using pharmaceutical antibiotics specific to strains of bacteria.
2. Being diligent with oral hygiene treatments, including regular debridement (removing thick deposits on the teeth) of biofilm, oral hygiene home instruction, lasers, ozone treatment and the use of natural antimicrobials and antifungals in the form of mouth rinses and toothpaste. These methods hinder the microorganisms from doubling in five hours.
3. Putting in new fillings using biocompatible dental materials.
4. Removing infected teeth as well as debriding any jaw bone cavitational sites.
5. Where sinus infections are prevalent, applying sinus hygiene methods such as sinus irrigation with saline.
In conclusion
Evidence-based science has proven the connection of the oral condition to chronic systemic disease, including autoimmune disease. Prevention continues to be the primary focus in our dental/medical clinic in regards to both dental and systemic conditions. We also believe strongly in educating our patients and on their responsibility and commitment to partnering with us in ensuring optimal health.