When the teeth are not cleaned properly by regular brushing and flossing, bacterial plaque accumulates, and becomes mineralized by calcium and other minerals in the saliva transforming it into a hard material called calculus (tartar) which harbors bacteria and irritates the gingiva (gums). Also, as the bacterial plaque biofilm becomes thicker this creates an anoxygenic environment which allows more pathogenic bacteria to flourish and release toxins and cause gingival inflammation. Alternatively, excessive injury to the gums caused by very vigorous brushing may lead to recession, inflammation and infection. Pregnancy, uncontrolled diabetes mellitus and the onset of puberty increase the risk of gingivitis, due to hormonal changes that may increase the susceptibility of the gums or alter the composition of the dentogingival microflora.^{[citation needed]} The risk of gingivitis is increased by misaligned teeth, the rough edges of fillings, and ill fitting or unclean dentures, bridges, and crowns. This is due to their plaque retentive properties. The drug phenytoin, birth control pills, and ingestion of heavy metals such as lead and bismuth may also cause gingivitis.^{[citation needed]}

The sudden onset of gingivitis in a normal, healthy person should be considered an alert to the possibility of an underlying viral aetiology,^{[citation needed]} although most systemically healthy individuals have gingivitis in some area of their mouth, usually due to inadequate brushing and flossing.
Prevention

Gingivitis can be prevented through regular oral hygiene that includes daily brushing and flossing. Mouth wash is optional, usually using a saline solution (water and salt) or chlorhexidine. Rigorous plaque control programs along with periodontal scaling and curettage also have proved to be helpful.

Researchers analyzed government data on calcium consumption and periodontal disease indicators in nearly 13,000 people representing U.S. adults. They found that men and women who had calcium intakes of fewer than 500 milligrams, or about half the recommended dietary allowance, were almost twice as likely to have gum disease, as measured by the loss of attachment of the gums from the teeth. The association was particularly evident for people in their 20s and 30s.

Research says the relationship between calcium and gum disease is likely due to calcium’s role in building density in the alveolar bone that supports the teeth.

Treatment
A dentist or dental hygienist will perform a thorough cleaning of the teeth and gums; following this, persistent oral hygiene is necessary. The removal of plaque is usually not painful, and the inflammation of the gums should be gone between one and two weeks. A gargling of brine water also helps. Oral hygiene including proper brushing and flossing is required to prevent the recurrence of gingivitis. Anti-bacterial rinses or mouthwash, in particular chlorhexidine digluconate 0.2% solution, may reduce the swelling and local mouth gels which are usually antiseptic and anaesthetic can also help. For serious cases, dentists can oversee special treatments that allow medication to be maintained around the teeth and in the sulcus long enough to kill gingivitis causing bacteria via non-invasive devices known as Perio Trays.