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Overview of Tooth Disorders


Bernard J. Hennessy

, DDS, Texas A&M University, College of Dentistry

Last full review/revision Mar 2021| Content last modified Mar 2021
Click here for the Professional Version
Topic Resources

Common tooth disorders include

Fractured, loosened, and knocked-out teeth are considered urgent dental problems, as are some toothaches. Tooth decay, which often leads to toothache and tooth loss, can be largely prevented with good oral hygiene, which helps remove plaque and prevent tartar buildup.

Plaque is a filmlike substance composed of bacteria, saliva, food debris, and dead cells. It occurs in everyone. Plaque is continually being deposited on teeth, day and night. After a tooth is cleaned, plaque develops on the surface of the tooth within about 24 hours. After about 72 hours, the plaque starts to harden and becomes tartar. Because plaque can encourage growth of the kind of bacteria that leads to tooth decay, it needs to be removed by daily brushing and flossing.

Tartar (calculus) is hardened (calcified) plaque that forms a white covering at the base of the teeth, particularly the tongue side of the front lower teeth and the cheek side of the upper molars (the teeth at the back of the mouth). Because tartar is formed from plaque, daily brushing to remove plaque can significantly reduce the buildup of tartar. However, once tartar has formed, it can be adequately removed only by a dentist or dental hygienist.

Although a healthy mouth can be maintained with meticulous brushing and flossing, limiting sugar intake and using fluoridated water also help reduce the risk of tooth decay.


The Language of Dentists

What Most People Call It

What Dentists Call It

Adult tooth

Permanent tooth


Aligners or orthodontic appliances

Baby tooth

Deciduous tooth

Back teeth

Molars and premolars




Orthodontic bands and wires or appliances






Composite filling

Composite resin

Eye teeth

Canines or cuspids



Front teeth

Incisors and canines



Gum disease

Periodontal disease, periodontitis, or gingivitis


Cleft lip

Laughing gas

Nitrous oxide

Lower jaw



Complete or partial denture (removable)

Roof of the mouth


Side teeth

Bicuspids or premolars

Silver filling

Amalgam restoration



Uneven bite

Upper jaw


Symptoms of Tooth Disorders

Pain affecting an individual tooth (toothache) is probably the most recognized symptom of a tooth disorder. A tooth may be painful all the time or only under certain circumstances, as when chewing or when tapped by a dental instrument. Pain in a tooth suggests tooth decay or gum disease. However, pain may also result when roots are exposed, when people chew too forcefully or grind their teeth (bruxism), or when a tooth is fractured. Sinus congestion can cause similar symptoms of pain in the area of the upper teeth.

Worn-down or loose teeth can be a symptom of gum disease or bruxism, a disorder characterized by frequent clenching or grinding of the teeth. Bruxism occurs mostly during sleep, so that the person is unaware of it, but it may also occur during the day. People who have bruxism must concentrate on not clenching or grinding their teeth during the day. Bruxism may lead to attrition. Attrition is the wearing away of the biting surfaces of the teeth. Attrition can also be caused by chewing abrasive foods or tobacco or by the wear that accompanies aging. Attrition may make chewing less effective.

Abnormally shaped teeth can be a symptom of genetic diseases, hormonal disorders, or infections acquired before teeth erupt. Teeth can be misshapen due to fractures or chipping caused by trauma to the mouth.

Abnormal tooth color is not the same as the darkening or yellowing of teeth that occurs as people grow older or expose their teeth to staining substances, such as coffee, tea, and cigarette smoke. Graying of a tooth may be a symptom of a previous infection within the tooth that has seriously damaged the pulp, which is the living center of the tooth. The same may occur when a permanent tooth replaces an infected baby tooth. Permanent discoloration of the teeth may occur if people took tetracycline before age 9 years or if their mothers took tetracycline during the second half of pregnancy. Excess fluoride ingestion during childhood can cause mottling of the hard outer surface of the tooth (the enamel).

Abnormal tooth enamel may be due to a diet containing insufficient vitamin D, as in rickets. Abnormal enamel may also be the result of a childhood infection (such as measles or chickenpox) occurring when the permanent teeth were forming. Abnormal enamel may also be due to gastroesophageal reflux or repeated vomiting, as occurs in bulimia nervosa, because the stomach acid dissolves the surface of the teeth. Swimmers who spend a lot of time in overchlorinated pools can lose tooth enamel, as can people who work with acids. Excess fluoride ingestion (fluorosis) during childhood can cause mottling of the enamel. Damaged tooth enamel can allow bacteria to more easily invade the tooth and form a cavity.

Cosmetic Dentistry

Cosmetic dentistry can dramatically improve a person’s appearance.

Bonding involves the attachment of tooth-colored fillings to natural teeth with minimal tooth preparation. Bonding is a conservative way to restore fractured or chipped teeth, to close spaces between the teeth, or to cover a portion of the tooth to change the shade, color, or shape. A mild acid solution is used to clean and mildly roughen the tooth surface so that a tooth-colored resin (generally made of a special type of plastic called a composite) can adhere to this surface. Bonding allows dentists to improve the appearance of the teeth without removing large amounts of tooth structure.

Porcelain veneers are similar to bonding, but they use tooth-colored porcelain instead of composite to mask discoloration or change the shape of the teeth. The process often requires two visits. An impression is made after the teeth are prepared. Porcelain veneers are then made in a dental prosthetic laboratory, sometimes using digital scanning and milling. The veneers are bonded to the teeth using a thin resin cement.

Bleaching, or tooth whitening, is a process to lighten teeth. The effectiveness of bleaching varies according to the original color of the teeth. Products used for home bleaching usually contain a hydrogen peroxide gel that is placed into a custom-made closely fitting mouth guard–like tray that holds the solution near the teeth. The bleaching agent is placed into the mouth for a few hours per day or even overnight for 2 to 4 weeks, depending on the concentration of the bleaching agent. Bleaching can also be done in a dentist’s office, in which the process is much quicker. People can also apply whitening strips themselves. These strips are often very effective and are safe to use at home. Toothpaste that contains whitening agents such as hydrogen peroxide and baking soda have been shown to whiten teeth but are often less effective than professionally applied products. The most common side effect of bleaching is tooth sensitivity. Bleaching may not be effective for people whose teeth are darkened or discolored because of cavities, because of a side effect of some drugs or diseases, or because of a tooth that has died.

More Information

The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  • Mouth Healthy: This general resource provides information on oral health, including nutrition and guidance on selecting products that carry the American Dental Association's seal of approval. There is also advice on finding a dentist and how and when to see one.

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
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Test your knowledge

Gum Recession
Gum recession is the loss of tissue at the gum line resulting in exposure of the root of the tooth. Which of the following is NOT a typical cause of gum recession?
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