What Causes Gum Disease?

Poor oral hygiene – Bacterial overgrowth: A large amount of bacteria lives in every mouth even if it is absolutely healthy. The critical factor for the mouth to remain healthy is our ability to keep the population of mouth bacteria under control with our daily oral hygiene. Inadequate tooth brushing, that fails to remove bacteria from the surface of teeth and gums, allows the accumulation of dental plaque. If the layer of dental plaque is not removed, it starts to harden and create dental calculus which can only be removed with professional dental cleaning. Dental calculus makes the teeth surface rough, helping the tooth plaque bacteria to accumulate more easily, and making it harder to clean them with tooth brushing and flossing.

Harmful bacteria: As the thickness of dental plaque increases, the composition of dental plaque in its lower layers starts to change in favor of anaerobic bacteria. This type of bacteria is linked with the inflammatory conditions that cause periodontal diseases. The bacteria species most implicated in periodontal disease and bone loss include: Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Other bacteria linked to gum disease are: Bacteroides forsythus, Treponema denticola, T. sokranskii and P. intermedia.

Several factors can increase the risk of developing periodontal diseases, but dental plaque is considered to be the root cause of gum diseases.

Although the bacteria of dental plaque are the ones that cause gum disease, the destruction of periodontal tissues is actually caused by our own body’s immune system response to chronic infections in the mouth. For this reason some researchers classify periodontal disease as one of the autoimmune disorders.

The steps of this destructive process are the following:

• Dental plaque’s composition changes from harmless aerobic bacteria towards gum disease causing anaerobic gram negative bacteria.
• Tooth plaque bacteria produce toxins causing irritation of the gingival tissues.
• Gums become red, swollen and bleed easily (gingivitis).
• Bacteria start to invade the crevices between the gum and teeth (sulcus) and infect the periodontal tissues.
• Gums inflammation causes a response from the body’s immune system, that over produces infection fighting factors called cytokines causing further inflammation.
• Immune system’s cells such as white blood cells, macrophages and lymphocytes, in their effort to fight the infection, attack the person's own infected cells and periodontal tissues.
• Cytokines trigger the production of an enzyme called collagenase, which breaks down collagen, which is a main ingredient of the jaw bone tissues surrounding teeth and the connective tissue (periodontal ligament) that holds teeth in place.
• Deep periodontal pockets are formed and irreversible bone loss occurs (periodontitis). Without proper treatment teeth will become loose and will be lost.

While bacterial plaque is the primary cause of periodontal disease, several other secondary causes can contribute in developing periodontal diseases. It is not clear if the following conditions are actual causes of gum disease, but they are believed to increase the risk, severity, and speed of gum disease development:

Medications

Usage of several types of medications is included among the causes of periodontal diseases. Medications such as blood pressure medicines, steroids, some types of anti-seizure drugs, cancer treatment drugs, some hypertension medicines and oral contraceptives can all affect the gums, making them more susceptible to gum disease.

Some of the drugs, such as antidepressants and some heart medicines, reduce the flow of saliva which is known to have a protective effect for teeth and gum tissue lowering the mouth’s defence to infections. Others cause an overgrowth of gum tissue, so that removing plaque becomes more difficult, promoting the development of gingivitis. Always inform your dentist about any medications you take, so that he can advice you on additional gum disease preventive measures, if needed.

Medical conditions

• Diabetes is a disease that causes fluctuations at the levels of sugar in the blood. Patients are at higher risk for developing infections such as periodontal diseases, because of diabetes impairing the function of certain immune cells and decreasing the production of collagen and bone. Patients with uncontrolled diabetes are not only at higher risk of gum disease, but they may also experience more severe gum infections, difficult healing and a greater loss of bone and connective tissues. Diabetes is the #1 systemic condition increasing susceptibility to periodontal disease.
• Systemic diseases that affect the body’s immune response such as cancer, leukemia or HIV make people more susceptible to periodontal disease.
• Autoimmune conditions (Crohn's disease, multiple sclerosis, rheumatoid arthritis, lupus erythematosus, CREST syndrome) have also been associated with a higher incidence of periodontal disease.
• Osteoporosis - The loss of minerals from bones’ structures, caused by osteoporosis, may make bones supporting the teeth more vulnerable to bacterial infection, increasing the risk of gum disease and tooth loss.
• Vitamin deficiencies - Vitamin C has antioxidant effects that help minimize the damage caused by tissue-destroying oxidants in periodontal disease. It also contributes in the mechanisms used by the human body to repair connective tissues.Vitamin C deficiency (scurvy) can cause inflamed, bleeding gums. Niacin deficiency (pellagra) also leads to inflamed, bleeding gums and a predisposition to certain mouth infections, such as periodontal diseases, oral thrush, or glossitis. Vitamin C and niacin supplements, and a diet rich in fresh fruits and vegetables can help prevent gum disease.
• Viral infections can cause gingivitis. Acute herpetic gingivostomatitis is a painful viral infection of the gums and other parts of the mouth caused by the herpes virus.
• Fungal infections can cause gingivitis as well. Oral thrush (candidiasis) is a fungal infection in which the overgrowth of fungi, particularly Candida albicans, forms a white film that irritates the gums.

Smoking/Tobacco Use

Smoking is considered as one of the most significant behavioral factors in the development and progression of periodontal disease. Smokers show 2-7 times higher possibility to develop periodontitis than non smokers.

Smoking reduces the effectiveness of the immune system, suppressing the production of antibodies directed against some of the harmful bacteria, allowing them to grow uncontrolled and cause gum disease. Smoking has been found to promote inflammation and bone loss. Quitting smoking must be a part of any prevention or treatment plan for periodontal disease.

Impacted Wisdom Teeth (Pericoronitis)

Wisdom teeth that have failed to erupt or have only partially erupted from gums are usually responsible for the inflammation and infection of the gums surrounding the crown of the impacted tooth. This type of localized periodontal disease, called Pericoronitis, is commonly resolved with the extraction of the wisdom tooth.

Human Transmission

Harmful bacteria that cause gum disease can be transmitted from one person to another. If a family member has periodontal disease, the risk is increased for the rest of the family members. Avoid kissing a person you know having gum disease, and never share your toothbrush.

Several other factors increase the risk for periodontal disease, by either contributing to the formation of bacterial plaque or/and by reducing the body’s ability to respond to bacterial infections.