Dentine hypersensitivity, commonly known as sensitive teeth, occurs when the hard enamel layer no longer covers the entire exposed surface of teeth, permitting access to the softer dentine layer underneath; the result is discomfort or pain, either momentary or lasting for up to several hours, usually triggered by brushing your teeth, cold air currents, or taking food or drink that is either cold, hot, sweet or acidic.
The causes of sensitive teeth vary in nature and gravity, but they typically involve either damage to the teeth’s enamel layer, or gum recession. A thin, mineralized layer that covers the crown, the visible part of the tooth, enamel can be demineralized and dissolved through the action of acids; this leads to sensitive teeth and, eventually, dental caries. Poor oral hygiene, low salivary flow rate, and frequent consumption of sugar, starches, or acidic foods and beverages are the most common causes of enamel demineralization.
Enamel can also be eroded or cracked by mechanical forces, with similar consequences. Erosion is often caused by inadequate tooth brushing and by gnashing of teeth. In order to prevent toothbrush abrasion, avoid brushing and flossing your teeth too aggressively, using a hard toothbrush, brushing from side to side, and brushing or flossing soon after consuming acidic foods or beverages. If you are in the habit of grinding your teeth, which may occur unconsciously during sleep, consult a health care professional, and consider using a mouthguard while sleeping.
Although it is the hardest substance in the human body, enamel may be accidentally chipped or cracked; since enamel does not grow back, such damage is irreversible by natural means, and medical intervention is necessary. Cracks are usually caused by biting on hard objects, and originate on the biting surface of the tooth, extending downwards. Enamel erosion, however, typically occurs at the base of the crown, near the gum line, where the enamel layer is at its thinnest.
Another common cause of sensitive teeth is gum recession; gums may shrink and recede from the tooth’s crown for various reasons, exposing the upper part of the root, which is not protected by enamel. Gum recession is usually caused by excessive or aggressive brushing and flossing, gum disease, hereditary low mass or consistency of gum tissue, tooth crowding or other abnormal tooth position issues, and even metal piercings that rub against the gums.
In the case of gum disease, the recession may be hidden from view by swelling; otherwise, gum recession can usually be observed through careful self-examination, as enamel has a different, lighter color than the cementum which covers the root. Effectively dealing with receding gums requires medical intervention, so consult your dentist for advice. You should regard sensitivity as a warning sign, and seek immediate medical assistance; if left untreated, gum recession can lead to dental root caries and even bone loss around the root.
Sensitive teeth constitute one of the most common oral health issues, and the condition is often the harbinger of more serious problems. Inadequate oral hygiene, whether insufficient or excessive, is an important risk factor; however, various other medical conditions, heredity, and physical trauma can also lead to dentine hypersensitivity. Prompt action and frequent dental check-ups are your best means of dealing with sensitive teeth and avoiding dangerous complications.