● Reasons for removal of calculus
When calcification occurs, the calculus that has become petrified plaque, a mass of bacteria, cannot be removed with a toothbrush once it has formed. Since the calculus is pathogenic like plaque, it is desirable to remove it from the mouth.

● Plaque (plaque biofilm) becomes calculus
Calculus does not occur suddenly one day. Calculus is produced when plaque attached to the surface of a tooth becomes petrified and hard. Plaque is a mass of bacteria formed from whitish cavity bacteria and periodontal disease bacteria. During calcification to restore enamel dissolved by food or cavity bacteria, the area where plaque is attached becomes calculus.

● What is plaque (plaque biofilm)?
It is a mass of bacteria adhering to the surface of teeth. Because it is sticky, it adheres firmly to the surface of the teeth and cannot be removed by strong gargling. It is said that there are about 600 kinds of bacteria in plaque and about 100 million – 200 million bacteria per 1 mg of plaque. Thus, to prevent plaque formation, bacteria must be sterilized and physically removed by brushing or flossing.

● Salivary phosphate and calcium contribute to calcification
Saliva has various functions such as moisturizing the mouth and making it easier to eat, washing away food scraps and plaque in the mouth, protecting the body from foreign substances and bacteria, and protecting teeth by promoting enamel calcification. Even before humans brushed their teeth, and throughout the evolution of all animals that did not brush their teeth, saliva helped to protect our precious teeth and mouth. Also, our saliva is rich in inorganic components such as phosphorus and calcium. These are, so to speak, the substances that repair the enamel and are responsible for the calcification of the enamel.

● The time it takes for plaque to calcify
It takes some time for the plaque on the tooth surface to calcify. Calcification begins between 2 and 14 days and is complete after about 8 to 15 days.

● Even if you have saliva, if you don’t have plaque, calculus is not formed.
As mentioned earlier, calculus is a calcified mass of bacterial plaque, and even if there is a lot of saliva that contains phosphorus and calcium, calculus is not formed without the plaque. To prevent calculus formation, you need to remove plaque.

● Can’t calcification be prevented?
Calcification in the mouth is an essential part of maintaining healthy enamel and is difficult to control. For example, if you decrease the secretion of saliva, which is responsible for calcification, your mouth will be short of materials such as phosphorus and calcium, so you can suppress calcification of plaque. However, it also leads to the inhibition of enamel regeneration, leading to the dissolution of teeth, which is not a good thing. In addition, saliva has many functions other than enamel repair, such as antibacterial and bactericidal effects, so it is very important that saliva is secreted normally.

● Sites prone to calculus formation
To effectively prevent calculus formation, it is important to know in advance where calculus formation is likely to occur. Calculus is not attached in random, and there is always site specificity. The clue is where the salivary glands are located. The opening of the salivary glands is common to all people as a common site of calculus. In our mouth, there are three salivary glands, called the three major salivary glands, that produce saliva at rest. The opening of these salivary glands (where saliva is secreted) — behind the lower front teeth and on both buccal sides of the upper back teeth — is prone to calculus formation.

● Method for preventing calculus formation
As mentioned above, calculus is a substance caused by calcification of plaque. Calcification process cannot be stopped because it is essential to maintaining a healthy oral environment. However, it is possible to suppress the deposition of plaque. There is no disadvantage to remove plaque. Also, if plaque is not present, calculus does not form, and the risk of periodontal disease is greatly reduced.

It can be said that removing plaque is the best way to suppress the deposition of calculus. Since plaque is a mass of bacteria such as dental cavity bacteria and periodontal disease bacteria, sterilization of those bacteria is a very effective method. Physical removal by brushing food scraps and formed plaque with a toothbrush or floss is also effective. For areas where floss or toothbrush cannot reach, it is effective to use a disinfectant that penetrates and sterilizes plaque.

In other words, the combination of brushing and flossing with a disinfectant-containing toothpaste and the occasional self-cleaning action of saliva is considered to be the most effective in removing the bacterial mass and plaque that cause calculus.

● Points
(1) The cause of calculus is calcified plaque.
(2) Plaque is a mass of bacteria such as dental cavity bacteria and periodontal disease bacteria.
(3) Sterilizing these bacteria and removing plaque can help prevent calculus formation
(4) Saliva washes away food scraps, dental plaque, bacteria, etc. Saliva secretion leads to prevention of forming plaque and calculus.
(If plaque, a mass of bacteria, has been removed, a lot of saliva will not turn into calculus.)