Periodontology – Calculus

Calculus or tartar is a type of dental plaque which hardens over time. Calculus is occurs due to the collection of minerals, which are created by saliva and gingival crevicular fluid in the plaque on the teeth. This precipitation process actually kills off the bacterial cells which are found within the dental plaque. The rough and hard surface which forms, however, acts as the ideal surface for additional plaque formation. This ultimately results in the buildup of calculus and compromises the health of the gums. It is possible for calculus to form along the gumline and within the narrow sulcus located between the teeth and the gingiva.

Calculus formation is associated with the clinical issues such as bad breath, receding gums and inflamed gingiva. Practicing good hygiene which includes twice daily brushing and flossing can aid in removing the plaque which results in calculus. Once the calculus has formed, it is too difficult to remove using a toothbrush. The buildup of calculus must be removed by a dental professional through the use of ultrasonic tools or dental hand instruments.

Formation of Calculus

Unfortunately, the processes of calculus formation from dental plaque is not well understood. The formation of supragingival calculus is more prevalent on the surfaces of the check, on the upper jaw molars, and on the tongue surfaces of the lower jaw incisors. Because of their proximity to the salivary glands, these areas experience an especially high flow of saliva. Subgingival calculus typically forms just below the gumline. It is usually dark in color because of the black-pigmented bacteria. The bacteria cells are coated in a layer of iron obtained from heme, which occurs during gingival bleeding. Dental calculus commonly forms in layers that are easily visible with the use of both electron and light microscopy. These layers are formed when the dental plaque calcifies. The calculus formation can vary quite drastically for every patient. There are numerous factors which influence how and where the dental calculus forms inside the mouth. Some of the most prevalent influencing factors include the following: age, gender, ethnic background, diet, location in the mouth, oral hygiene, bacterial plaque composition, genetics, dental care access, physical disabilities, systemic diseases, use of tobacco, drugs and medications.

When plaque accumulates, it can cause the gingiva to become inflamed and irritated. This is most often called gingivitis. When the gingiva is chronically irritated, there is a loss of the connective tissue fibers which attach the gums to the teeth and bone surrounding the teeth. When this occurs, it is called periodontitis. While dental plaque does not exclusively cause periodontitis, it is commonly associated with the condition. Plaque, which stays in the oral cavity for extended periods of time, eventually calcifies and turns to calculus. Calculus is particularly bad for gingival health as it will lead to the additional formation of plaque.

When plaque is supragingival, or above the gums, the bacteria content has higher levels of aerobic bacteria and yeast. This bacteria is able to survive in environment containing oxygen. Subgingival plaque also contains a greater amount of anaerobic bacteria. This includes bacteria which is unable to exist in an environment containing oxygen. Various types of anaerobic plaque bacteria secrete antigenic proteins and trigger an inflammatory response in the periodontium. The periodontium include the specialized tissues which support and surround the teeth. When the periodontium is inflamed for extended periods of time, it can result in the loss of bone and weakened gingival fibers, those that attach the teeth to the gums. These side effects are chronic issues that are often associated with periodontitis. Nearly all patients who have periodontitis, demonstrate high levels of subgingival calculus deposits.