Periodontitis

Periodontitis, formerly known as Pyorrhea alveolaris, is the name of a collection of inflammatory diseases affecting the tissues that surround and support the teeth. Periodontitis involves progressive loss of the bone around teeth which may lead to loosening and eventual loss of teeth if untreated. Periodontitis is caused by bacteria that adhere to and grow on tooth surfaces (microbial plaque or biofilms), particularly in areas under the gum line. Periodontitis is very common in most populations but the severe forms of the disease are less common (less than 10% in the U.S.). Dentists diagnose periodontitis by inspecting the tissues around the teeth with a probe and by radiographs to detect bone loss around the teeth. Although the different forms of periodontitis are bacterial diseases, a variety of factors affect the severity of the disease. Important "risk factors" include smoking, poorly controlled diabetes, and inherited (genetic) susceptibility.

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Etiology

Periodontitis is an inflammation of the periodontium -the tissues that support the teeth in the mouth. The periodontium is comprised of:

• the gingiva, or gum tissue
• the cementum, or outer layer of the roots of teeth
• the alveolar bone, or the bony sockets into which the teeth are anchored
• the periodontal ligaments (PDLs), which are the connective tissue fibres that connect the cementum and the gingiva to the alveolar bone.

  If left untreated, periodontitis causes progressive bone loss around teeth, looseness of the teeth and eventual tooth loss. Periodontitis is a very common disease affecting approximately 50% of U.S. adults over the age of 30 years. Periodontitis is thought to occur in people who have preexisting gingivitis - an inflammation that is limited to the soft tissues surrounding the tooth and does not cause bone loss.

The primary etiology, or cause, of gingivitis is the accumulation of a bacterial matrix at the gum line, called dental plaque. In some people, gingivitis progresses to periodontitis - the gum tissues separate from the tooth and form a periodontal pocket. Subgingival bacteria (those that exist under the gum line) colonize the periodontal pockets and cause further inflammation in the gum tissues and progressive bone loss. Examples of secondary etiology would be those things that cause plaque accumulation, such as restoration overhangs and root proximity.  

If left undisturbed, bacterial plaque calcifies to form calculus. Calculus above and below the gum line must be removed completely by the dental hygienist or dentist to treat gingivitis and periodontitis. Although the primary cause of both gingivitis and periodontitis is the bacterial plaque that adheres to the tooth surface, there are many other modifying factors. One of the most predominant risk factors of periodontal disease is tobacco use. Another very strong risk factor is one's genetic susceptibility. Several conditions and diseases, including Down syndrome, diabetes, and other diseases that affect one's resistance to infection also increase susceptibility to periodontitis.

Another factor that makes periodontitis a difficult disease to study is that human host response can also affect the alveolar bone resorption. Host response to the bacterial insult is mainly determined by genetics, however immune development may play some role in susceptibility.

Signs and symptoms

Symptoms may include the following:

• occasional redness or bleeding of gums while brushing teeth, using dental floss or biting into hard food (e.g. apples) (though this may occur even in gingivitis, where there is no attachment loss)
• occasional gum swellings that recurs
• halitosis, or bad breath, and a persistent metallic taste in the mouth
• gingival recession, resulting in apparent lengthening of teeth. (This may also be caused by heavy handed brushing or with a stiff tooth brush.)
• deep pockets between the teeth and the gums (pockets are sites where the attachment has been gradually destroyed by collagen-destroying enzymes, known as collagenases)
• loose teeth, in the later stages (though this may occur for other reasons as well)

Patients should realize that the gingival inflammation and bone destruction are largely painless. Hence, people may wrongly assume that painless bleeding after teeth cleaning is insignificant, although this may be a symptom of progressing periodontitis in that patient.

Prevention

Daily oral hygiene measures to prevent periodontal disease include:

• brushing properly on a regular basis (at least twice daily), with the patient attempting to direct the toothbrush bristles underneath the gum-line, so as to help disrupt the bacterial growth and formation of subgingival plaque and calculus.
• flossing daily and using interdental brushes (if there is a sufficiently large space between teeth), as well as cleaning behind the last tooth in each quarter.
• using an antiseptic mouthwash. Chlorhexidine gluconate based mouthwash or hydrogen peroxide in combination with careful oral hygiene may cure gingivitis, although they cannot reverse any attachment loss due to periodontitis. (Alcohol based mouthwashes may aggravate the condition).
• regular dental check-ups and professional teeth cleaning as required. Dental check-ups serve to monitor the person's oral hygiene methods and levels of attachment around teeth, identify any early signs of periodontitis, and monitor response to treatment.

Typically dental hygienists (or dentists) use special instruments to clean (debride) teeth below the gumline and disrupt any plaque growing below the gumline. This is a standard treatment to prevent any further progress of established periodontitis. Studies show that after such a professional cleaning (periodontal debridement), bacteria and plaque tend to grow back to pre-cleaning levels after about 3-4 months. Hence, in theory, cleanings every 3-4 months might be expected to also prevent the initial onset of periodontitis. However, analysis of published research has reported little evidence either to support this or the intervals at which this should occur.^[1] Instead it is advocated that the interval between dental check-ups should be determined specifically for each patient between every 3 to 24 months.^[2][3]

Nonetheless, the continued stabilization of a patient's periodontal state depends largely, if not primarily, on the patient's oral hygiene at home if not on the go too. Without daily oral hygiene, periodontal disease will not be overcome, especially if the patient has a history of extensive periodontal disease.

Treatment of established disease

  If good oral hygiene is not yet already undertaken daily by the patient, then twice daily brushing with daily flossing, mouthwashing and use of an interdental brush needs to be started. Technique with these tools is very important. Aged persons may find that use of these interdental devices more necessary and easier, since the gaps between the teeth may become larger.

A dental hygienist or a periodontist can use professional scraping instruments, such as scalers and currettes to remove bacterial plaque and calculus (formerly referred to as tartar) around teeth and below the gum-line. There are devices that use a powerful ultra-sonic vibration and irrigation system to break up the bacterial plaque and calculus. Local anesthetic is commonly used to prevent discomfort in the patient during this process.

It is difficult to induce the body to repair bone that has been destroyed due to periodontitis. Much depends on exactly how much bone was lost and the architectural configuration of the remaining bone. Vertical defects are those instances of bone loss where the height of the bone remains somewhat constant except in the localized area where there is a steep, almost vertical drop. Horizontal defects are those instances of more generalized bone loss, resulting in anywhere from mild to severe loss of initial bone height. Sometimes bone grafting surgery may be tried, but this has mixed success. Bone grafts are more reliable in instances of vertical defects, where there might be a sufficient "hole" within which to place the added bone. Horizontal defects are rarely if ever able to be grafted properly, as there is nowhere to secure the bone.

Dentists sometimes attempt to treat patients with periodontitis by placing tiny wafers dispensing antibiotics underneath the gumline in affected areas. However, the general scientific consensus is that antibiotic treatment is of minimal value in treating bone loss due to periodontitis. It may help to recover about one millimeter of bone, but it is questionable if this is of significant therapeutic value.

Alternatively, regular subgingival flushing with an anti-calculus composition can dissolve subgingival calculus (tartar) thus facilitating natural healing without surgery. This process is widely used for supragingival tartar via tartar-control toothpastes. Subgingival application of an anti-calculus composition requires a subgingival syringe or an oral irrigator.

One such anti-calculus composition (Periogen) contains sodium tripolyphosphate, tetrapotassium pyrophosphate, sodium bicarbonate, citric acid and sodium fluoride.

In the composition, tetrapotassium pyrophosphate (TKPP) is a cleaning agent designed to clear away biofilms in order to facilitate chemical access to calculus. Sodium tripolyphosphate (STPP) acts as the anti-calculus agent, activated by sodium fluoride (.04%), providing a chelating action on the structure of the calculus.

Sodium bicarbonate and citric acid are product activators which assist in dissolving the composition in water for periodontal delivery via a subgingival syringe or oral irrigator with a periodontal tip.

Assessment and prognosis

Dentists or dental hygienists "measure" periodontal disease using a device called a periodontal probe. This is a thin "measuring stick" that is gently placed into the space between the gums and the teeth, and slipped below the gum-line. If the probe can slip more than 3 millimetres length below the gum-line, the patient is said to have a "gingival pocket" around that tooth. This is somewhat of a misnomer, as any depth is in essence a pocket, which in turn is defined by its depth, i.e., a 2 mm pocket or a 6 mm pocket. However, it is generally accepted that pockets are self-cleansable (at home, by the patient, with a toothbrush) if they are 3 mm or less in depth. This is important because if there is a pocket which is deeper than 3 mm around the tooth, at-home care will not be sufficient to cleanse the pocket, and professional care should be sought. When the pocket depths reach 5, 6 and 7 mm in depth, even the hand instruments and cavitrons used by the dental professionals cannot reach deeply enough into the pocket to clean out the bacterial plaque that cause gingival inflammation. In such a situation the pocket or the gums around that tooth will always have inflammation which will likely result in bone loss around that tooth. The only way to stop the inflammation would be for the patient to undergo some form of gingival surgery to access the depths of the pockets and perhaps even change the pocket depths so that they become 3 or less mm in depth and can once again be properly cleaned by the patient at home with his or her toothbrush.

If a patient has 5 mm or deeper pockets around their teeth, then they would risk eventual tooth loss over the years. If this periodontal condition is not identified and the patient remains unaware of the progressive nature of the disease then, years later, they may be surprised that some teeth will gradually become loose and may need to be extracted, sometimes due to a severe infection or even pain.

According to the Sri Lankan Tea Labourer study, in the absence of any oral hygiene activity, approximately 10% will suffer from severe periodontal disease with rapid loss of attachment (>2 mm/year). 80% will suffer from moderate loss (1-2 mm/year) and the remaining 10% will not suffer any loss.^[4][5]

See also

• Actinomyces naeslundii - a kind of bacterium
• Calculus (dental) - tartar
• Campylobacter - a kind of bacterium
• Dental plaque - bacterial biofilm that clings to teeth
• Edentulism - condition of one or more missing teeth
• Gingivitis - inflamation of the gums
• Gum graft - a type of gum surgery, to replace lost gum tissue
• Head and neck anatomy - biological composition above the shoulders
• Osteoimmunology - studies the immune system with respect to bones
• Oral microbiology - study of the microorganisms of the oral cavity

Further reading

• Pihlstrom, BL; Michalowicz BS, Johnson NW (2005). "Periodontal diseases". Lancet 366 (9499): 1809-20. ISSN 0140-6736. PMID 16298220.