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n.

The science concerned with the diagnosis, prevention, and treatment of diseases of the teeth, gums, and related structures of the mouth and including the repair or replacement of defective teeth.

An autonomous branch of biomedical science that is concerned with the prevention, diagnosis, and treatment of diseases and abnormalities of the teeth, jaws, oral cavity, and adjacent structures.

Dental caries (tooth decay) is one of the most prevalent diseases affecting humans, and the greatest portion of the dentist's time and efforts is expended on treating dental decay and its consequences. In addition to caries, teeth can be damaged by trauma, erosion, and abrasion. Restorative dentistry encompasses efforts to conserve and restore decayed, defective, missing, and traumatically injured teeth.

Significant advances have been made in the practice of restorative dentistry. Development of high-speed, air-driven turbines combined with rotary cutting instruments fashioned from diamonds and ultrahard steel permits the rapid removal of tooth structure with little discomfort to the patient. In addition, many new materials for restorations and impression taking have become available. Especially important is the availability of composite resins which have sufficient strength to withstand biting and chewing pressures.

Seven branches of specialization are recognized by the American Dental Association: oral surgery, orthodontics, pedodontics, periodontics, prosthodontics, oral pathology, and public health dentistry. Other subspecialties such as oral medicine, dental radiology, and periodontal prosthetics exist but are not recognized.

Oral surgery treats diseases and abnormalities of the maxillofa-cial region by surgical means. Oral surgeons treat a wide variety of problems by removing teeth, reducing bone fractures, removing cysts, tumors, and growths, and correcting congenital anomalies and malformation of the structures of the maxillofacial region.

Orthodontists deal with abnormalities in tooth position and jaw relationships that result in facial disharmony and malfunction. The objective of orthodontic treatment is to establish normal occlusion and facial harmony. The teeth are repositioned and the jaws modified through the use of mechanical force applied with fixed or removable appliances. Successful treatment results in normal shape and expression of the mouth and lips, aids in enunciation and the sounding of words, and permits proper mastication.

Pedodontics is the branch of dentistry concerned with the detection, prevention, and treatment of oral and dental diseases and abnormalities in children. The deciduous or primary teeth are very small and have shapes which differ from those of adult teeth; special procedures and materials are required for their conservation and restoration.

Periodontics is the branch of dentistry devoted to the study, prevention, diagnosis, and treatment of diseases of the tissues supporting the teeth: gingiva (gum tissue), alveolar bone, periodontal ligament, and cementum. Periodontal diseases include gingivitis, periodontitis (sometimes called pyorrhea), primary and secondary occlusal traumatism, gingival hyperplasia, and periodontal atrophy. Several types of anaerobic gram-negative microorganisms are thought to be associated with chronic periodontitis. See also Periodontal disease.

Prosthodontics is the branch of dentistry devoted to the construction and replacement of oral structures with artificial substitutes. The replacement of teeth and other oral structures is necessitated by congenital abnormalities, loss of teeth from disease or trauma, and destruction of teeth or jaws or other parts of the mouth by surgical management of neoplasms or trauma.

Oral pathology is concerned with the detection and diagnosis of the diseases of the teeth, oral cavity, and jaws, and also with the oral manifestations of systemic diseases. See also Pathology.

Public health dentistry is defined as the science and art of preventing and controlling dental diseases and promoting dental health through organized community efforts. It comprises research, education, prevention, diagnosis, prescription, treatment of problems related to dentistry, and evaluation of community dental care. See also Tooth disorders.

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Dentistry is the art or science of treating diseases of the teeth and of the gums around them. As with medicine, dentistry is subdivided into a number of specialities. Oral surgery includes tooth extractions and operations on the jaw bones and the soft tissues of the mouth. Oral medicine deals with the treatment of local or systemic diseases affecting the mouth. Restorative dentistry involves replacement of parts of teeth or missing teeth. Fillings may be made from ‘plastic’ materials, such as amalgams or tooth-coloured composite resins, or pre-cast inlays; larger restorations may require metal or ceramic crowns. Restorative dentistry also includes endodontics (treating the pulps or root canals of teeth) and prosthodontics. In prosthodontics, missing teeth are replaced either with fixed bridges (using crowns placed on healthy teeth to support the ‘pontic’ that replaces the missing tooth or teeth) or removable dentures (false teeth) that may be partial or complete, depending on whether some or all of the natural teeth have been lost. Periodontics covers treatment of diseases of the gums (gingivitis) and other tissues around the teeth (periodontitis). Orthodontics is the correction of misalignment of teeth using appliances (‘braces’), which may be held by brackets glued to the teeth (fixed appliances) or retained with wire clasps (removable appliances). Paedodontics covers all aspects of dentistry in children.

The earliest references to teeth and dental diseases are inscriptions written on clay tablets around 5000 years ago in Mesopotamia. The first known dentist was Hesi-Re. He lived in Egypt around 3000 years ago, and was described as ‘the greatest of the physicians who treat teeth’. In ancient times, dental ‘treatment’ consisted mainly of tooth cleaning and perhaps some tooth extractions. Dentures (false teeth) first appeared in Sidon (Lebanon) and Tuscany around 630 bce. Here, gold bands and wires were used to attach false teeth (usually carved from ivory) to adjacent healthy teeth. The Romans were very oral hygiene-conscious. They washed their teeth and cleaned them with tooth powders (dentifrices). In ancient Greece and Rome, as in Egypt, dentistry was performed by general physicians. Practitioners were skilled in restoring carious teeth with gold and replacing missing teeth with false ones. These false teeth were ridiculed by the poet Martial, who wrote in the first century ad:

Lucania has white teeth; Thaïs brown. How comes it? One has false teeth, one her own.

During the Dark and Middle Ages in Europe (approximately from 500-1500 ad), progress in medicine halted and there were no real advances for nearly 1000 years. However, during this period knowledge was sustained by Islamic scholars such as Albucasis, who wrote extensively on teeth and tooth cleaning. The importance of oral hygiene was widely recognized in the Orient. During this period Hindus and the Chinese developed various dental treatments and complex surgical procedures. In Europe, by the fifteenth century ‘dentistry’ was undertaken by barber-surgeons, physicians or apothecaries, blacksmiths, and other ‘tooth-drawers’. Herbal concoctions were the main ‘remedies’ for toothache and ‘treatment’ was confined mainly to extractions. The upper classes cleaned their teeth with cloth or sponges, and some even had gold or silver toothpicks. These were often hung round the owner's neck as an item of jewellery.

Knowledge blossomed in the Renaissance. Many of the new anatomical texts, such as Andreas Vesalius' great work De humani corporis fabrica, contained sections on teeth. Some purely dental texts were published in the sixteenth and seventeenth centuries, but the foundations of modern dental practice were laid in Pierre Fauchard's Le Chirurgien Dentiste (1728). Fauchard's book was a comprehensive discourse on a wide range of treatments. He described techniques for scraping out caries and filling the cavities with soft metals such as tin, lead, or gold. His book also gave rise to the modern term ‘dentist’ or ‘dental surgeon’.

Prior to 1844, there were no anaesthetics to abolish the pain of surgery. However, opium and laudanum (tincture of opium) were freely available ‘over the counter’. Dorothy Wordsworth (sister of the poet William) wrote: ‘I had toothache in the night. Took laudanum.’ In 1844, an American dentist, Horace Wells, was the first person to experience tooth extraction under nitrous oxide analgesia. Two years later, William Morton extracted a tooth under ether anaesthesia. In 1884, a Dr Nash was the first person to fill a tooth using cocaine injected as a local anaesthetic. In 1905, cocaine was replaced by the synthetic drug novocaine (procaine). This in turn was replaced by lignocaine (lidocaine), which is in use today.

In the eighteenth century, dentures were hand-carved from materials such as ivory, and so did not fit well. Springs were sometimes used to help improve the stability of these loose dentures. However, dentures did not improve until the invention (by Nelson Goodyear) of a hardened rubber (‘Vulcanite’) which allowed closely-fitting denture bases to be constructed on casts made from impressions of the patient's mouth. As well as fitting better, vulcanite dentures were cheaper to make.

Other developments in the nineteenth century included the reclining dental chair, amalgam fillings (which were controversial even in the 1850s), and the treadle engine for driving the dental drill. The first electric-powered dental drill was invented in 1868. Many of the technical aspects and skills of dentistry were established by the end of the nineteenth century and some have remained more or less unaltered to the present day. The principles of cavity cutting, formulated by G. V. Black in the 1880s, have been supplanted only recently with the advent of adhesive filling materials. Developments in the twentieth century included improvements in dental materials, the introduction of the ‘high-speed’ drills (powered by compressed air), and greater emphasis on instrument sterility and cross infection control.

The modern dentist is part of a team, which includes a dental nurse (dental assistant), a technician, and ancillary operators such as dental hygienists, dental therapists, and dental radiographers. Dentistry is changing from being a pain-relief and patch-up service to a profession which places emphasis on prevention of tooth decay (dental caries) and gum disease (gingivitis and periodontitis). These diseases are largely preventable with good diet and effective oral hygiene. Their effects can be minimized by early diagnosis and treatment. Fluoride can help prevent caries, by making the enamel more resistant to attack by plaque acids, but it can also cause staining or mottling of the teeth (fluorosis). Artificial fluoridation of water supplies would reduce the incidence of caries, especially amongst people with poor standards of oral hygiene. However, fluoridation of public water supplies is a controversial political issue. The recent improvements in dental health can be illustrated by data from Great Britain. In 1968, 37% of adults in England and Wales had no natural teeth. In Scotland in 1972, 44% of adults had lost all their teeth. By 1988, these figures had fallen to 20% in England and Wales and 26% in Scotland. These improvements were due mainly to the better dental health in people under 35 years of age.

In spite of these improvements in dental health, teeth are still extracted because of decay. General anaesthesia (GA) was widely used for tooth extraction in young children and in some adults with a fear of injections. In the UK, the use of GA for dental procedures has been restricted. This is intended to eliminate the small numbers of deaths each year associated with dental GA. Since 1998, GA can be administered only by suitably qualified anaesthetists in clinics where proper emergency facilities and staff are available. One alternative to GA is conscious sedation. Here, the patient is awake and can respond to verbal commands, but is ‘relaxed’. Sedation is produced using drugs such as a nitrous oxide- oxygen mixture, or tranquillizers such as diazepam (Valium), and is normally used along with appropriate local anaesthesia.

What of the future? The improvements in dental health must be sustained. A major priority is to find effective alternatives for injected local anaesthetics and replacements for the dental drill. One interesting area of development is the use of chemicals to remove caries without the need for drilling. The decay is dissolved by acids and the softened debris is scooped out. Laser technology, too, is developing and in time may replace the drill in restorative dentistry. The advent of adhesive, tooth-coloured fillings has revolutionized restorative dentistry. It is no longer necessary to cut large cavities for amalgam fillings. Instead, fillings can be placed with the minimum loss of healthy tooth substance. In prosthodontics, metal posts implanted in the jaw bones can be used to improve the support and efficiency of dentures. Nowadays, people live longer and can expect to have their natural teeth when they die. The science of dental gerontology has emerged to meet the dental needs of elderly people. Cosmetic dentistry, too, is a growth industry. Thin veneers can be used to correct defects on the outer surfaces of anterior teeth. The current trend of body adornment has extended to teeth, and small gems or gold shapes (‘Twinkles’) can be glued to the tooth surface. But cosmetic dentistry is not new. Many societies in Africa and America file the teeth for decorative and ceremonial purposes. In the ninth century the Mayans placed decorative inlays in anterior teeth. These inlays of semi-precious stones were fixed into cavities cut with a simple bow drill. Such skills were not introduced to Europe until many centuries later.

— Robin Orchardson

Bibliography

• Hillam, C. (1990). The roots of dentistry. British Dental Association, London.
• Ring, M. E. (1993). Dentistry: an illustrated history. H. N. Abrams Inc., New York

See also teeth.

n

The science and art of preventing, diagnosing, and treating diseases, injuries, and malformations of the teeth, jaws, and mouth and of replacing lost or absent teeth and associated structures.

For more information on dentistry, visit Britannica.com.

In the eighteenth century, the practice of dentistry was primarily concerned with extracting diseased teeth, not protecting healthy ones. When George Washington was inaugurated in 1789 at the age of 57, he had only one natural tooth left. State-of-the-art dental care in his day consisted of yanking out rotten teeth without benefit of painkillers and crafting awkward dentures from elk and cow teeth, and from the ivory tusks of elephants, hippopotami, and walruses. (Washington owned several pairs of such dentures, though none made of wood, despite the myth.) Dr. A. A. Plantou, a Frenchman who had emigrated to Philadelphia, introduced porcelain teeth to the United States in 1817. (France was the center of dentistry in the eighteenth century; American dominance in the field began in the nineteenth century.) In the 1850s, Nelson Goodyear's invention of Vulcanite—an inexpensive hard rubber that could be molded to the shape of the jaw and fitted with porcelain teeth—finally made false teeth affordable for the average person.

The introduction of nitrous oxide ("laughing gas") in the early 1830s made extraction less painful, but correct dosages were hard to determine. Ether was first used in surgery in 1842 by Dr. Crawford W. Long (though the patent went to Drs. William Thomas Green Morton and Charles Thomas Jackson in 1846). Chloroform, discovered in the early 1830s by doctors in several countries, also began to be used as an anesthetic in dentistry. In 1884, Dr. William Stuart Halsted reported that morphine injected into the lower jaw resulted in complete numbness in six minutes. However, the drug was addictive and could cause localized tissue death (necrosis). It wasn't until 1905 and the invention of the first non-addictive anesthetic, novocaine ("new cocaine"), that dental work could be both safe and painless.

In 1855, Dr. Robert Arthur introduced a cohesive gold foil filling for teeth, produced by heating and cooling the metal to make it stronger. The first crowns were developed in 1880 by Dr. Cassius M. Richmond, who patented a porcelain tooth soldered to a gold body. The invention of the electric furnace (in 1894) and low-fusing porcelain (in 1898) made possible the first strong porcelain "jacket" crown, introduced in 1903.

The first dental school, the Baltimore College of Dental Surgery, was founded in 1840 in Maryland. For decades, however, dentists were not required to pass a test or obtain a license in order to practice. It took nearly one hundred years for dental education to develop its present form: three or four years of undergraduate study and four years of dental school, with a curriculum including medical science, technical training, and clinical practice.

The Mercury Controversy

Mercury compounds introduced to the United States in 1832 as a filling for the cavities left after dental caries are removed provoked a controversy that continues to the present day. Because the injurious effects of mercury poisoning—ranging from muscle tremors to hallucinations— were well known in the nineteenth century, many were fearful of the new treatment. Mercury still accounts for 50 percent of modern silver amalgam fillings, developed in 1895 by Dr. G. V. Black (known as "the father of scientific dentistry"). The other components are: 35 percent silver, about 15 percent tin (or tin and copper, for added strength), and a trace of zinc. In the late 1980s it was discovered that minute amounts of mercury vapor are released in chewing. A few years later researchers demonstrated the ill effects of silver amalgam in sheep (the mercury caused kidney malfunction) and human fetuses (mercury from mothers with silver fillings was found in the brain tissue of stillborn babies). Some worried patients have had all their amalgam fillings removed and replaced with porcelain inlays (developed in the late 1890s) or composite resin fillings (invented in the late 1930s). On the other hand, considering the long and widespread use of amalgam fillings—contained in the teeth of more than 100 million living Americans, and handled constantly by dentists—many experts believe such findings to be inconclusive. The American Dental Association (ADA) not only affirms the safety of dental amalgam but also claims that it is unethical for dentists to recommend removal of amalgam fillings from a patient's teeth "for the alleged purpose of removing toxic substances from the body." The ADA cites other studies, of dentists as well as patients, that show no correlation between amalgam fillings and kidney disease or nervous disorders.

Treating Tooth Decay

In the early nineteenth century, it was believed that decay (dental caries) originated on the surface of the tooth. In 1890, American dentist Willoughby D. Miller's ground-breaking work, The Micro-organisms of the Human Mouth, revealed that acids from dissolved sugars in foods decalcify tooth enamel, followed by bacterial action that destroys the bone-like dentin underneath that surrounds living tissue. This discovery led dentists to place more emphasis on oral prophylaxis—disease-preventive measures—as well as on proper sterilization of dental tools. Yet dental health nationwide remained less than optimum. During World War II, the Selective Service initially required each new armed forces recruit to have at least twelve teeth, three pairs of matching front teeth (incisors) and three pairs of chewing teeth (molars). When it turned out that one in five of the first two million men didn't qualify, all dental standards were dropped.

The addition of fluoride to city water systems, beginning in 1945 in Michigan and Illinois, sparked a major controversy. In 1942, a U.S. Public Health Service dentist, Dr. H. Trendley Dean, had determined that adding one part fluoride per million of drinking water reduced dental caries. By 1950, more than 50 cities had fluoridated their water supply. Then came the protests, most famously those of the John Birch Society, which believed the program to be a Communist plot to poison Americans. Others, including health food advocates, were concerned about potential poisons. Yet by the 1960s fluoride was in nearly 3,000 water systems serving 83 million people. By the end of the twentieth century, some 155 million Americans—62 percent of the population—had fluoridated water. Fluoride also has been added to many toothpaste and mouthwash brands.

In 1954 a team of scientists at the University of Notre Dame, led by Frank J. Orland, identified Streptococcus mutans as the bacteria that produces the acid that dissolves tooth enamel and dentin. The origin of gum (periodontal) disease was unknown until the mid-1960s, when bacterial plaque was found to be the culprit. Since the 1970s, biotechnology has helped the dental researchers known as oral ecologists to begin to identify some of the more than 400 species of microorganisms (mostly bacteria) that live in the mouth.

Dental Tools

Invented in 1895 in Germany, x-rays were demonstrated for dental use the following year in the United States by Dr. Charles Edmund Kells Jr., who also invented the automatic electric suction pump to drain saliva. (The first tool for saliva control was the rubber dental dam, invented in 1864 by Dr. Sanford C. Barnum.) Commercial x-ray equipment made for dentistry was first used in the United States in 1913. Other features of modern dental offices took many decades to achieve their present form. In 1832 James Snell developed the first dental chair, which included a spirit lamp and mirror to illuminate the patient's mouth. A major breakthrough in chair design occurred in 1954, with Dr. Sanford S. Golden's reclining model. John Naughton's Den-Tal-Ez chair, powered by hydraulic cylinders, was introduced in the 1960s. The first self-cleaning device to receive patients' spit was the Whitcomb Fountain Spittoon, marketed in 1867.

The electric-powered drill was invented in 1868 by George F. Green, a mechanic employed by the S. S. White Company. Inspired by the workings of the Singer sewing machine mass-produced a decade earlier, James Beall Morrison added a foot treadle and pulley system in 1871. But the drill was still very heavy, and dentists' offices were not wired for electricity until the late 1880s, when Dr. Kells first adopted the new technology. In 1953 a team at the National Bureau of Standards, led by Dr. Robert J. Nelson, finally developed a hydraulic-powered turbine drill that could achieve speeds of 61,000 revolutions per minute. (Today, electrically powered drill speeds of 400,000 revolutions per minute or more are common.) Speed is significant because it reduces not only the time it takes to remove caries but also the amount of pressure on the tooth.

Recent Developments

Since the mid-1980s composite resin fillings have grown increasingly popular in the United States as an alternative to amalgam. The first composite filling was developed in 1955 by Michael Buonocore and others, but the acrylic proved too soft for the stress caused by chewing. The addition of microscopic particles of glass or quartz to the plastic resin base in 1967 solved this problem. While composite resin is white—and therefore relatively invisible—it is not as long-lasting as silver amalgam, can be more costly for the patient, and requires greater skill on the dentist's part because it is applied in separate layers that must harden under a strong light.

Numerous advances in dental treatment in the late twentieth century have radically altered the field. Digital imagery of the teeth, transmitted through fiber optics from an x-ray sensor to a computer screen, offers a faster, safer, and more easily readable alternative to x-ray film. This process emits 90 to 95 percent less radiation than ordinary x-rays, and allows the image to be magnified and more easily stored, reproduced, and shared with other doctors. The first laser "drill" was approved by the FDA in 1997. Lasers burn through decay without vibration or pressure on the tooth. Other advances include "invisible" braces that attach to the insides of teeth, dental implants that anchor to the jaw to permanently replace missing teeth, and computer-generated tooth restorations. Cosmetic dentistry, including bonding (using composite resin to improve tooth shape and whiteness) and bleaching, has spawned business franchises devoted exclusively to these services.

Bibliography

Hoffmann-Axthelm, Walter, trans. H. M. Koehler. History of Dentistry. Chicago: Quintessence, 1981.

Jedynakiewicz, Nicolas M. A Practical Guide to Technology in Dentistry. London: Wolfe, 1992.

Jong, Anthony W., ed. Community Dental Health. St. Louis, Mo.: Mosby, 1988.

Prinz, Hermann. Dental Chronology: A Record of the More Important Historic Events in the Evolution of Dentistry. Philadelphia: Lea & Febiger, 1945.

Ring, Malvin E. Dentistry: An Illustrated History. New York: Abrams, 1985.

Weinberger, Bernhard W. An Introduction to the History of Dentistry. St. Louis, Mo.: Mosby, 1948.

Wynbrandt, James. The Excruciating History of Dentistry. New York: St. Martin's Press, 1998.

—Cathy Curtis

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Food and dental health interact, with each having effects on the other. Patterns of eating affect the health of the teeth and other tissues in the mouth, while the ability to chew a variety of foods without discomfort influences a person's nutritional state as well his or her enjoyment of eating.

Sugar and Dental Caries

The clearest link between food and dental health is between sugar consumption and caries (cavities). A study in the 1940s compared the dental health of children in an area of northern India, where food was scarce and malnutrition common, to that of better-nourished children in Lahore and in Rochester, New York. The poorly nourished children had the fewest cavities. Subsequent research confirmed that populations who enjoyed a good nutritional status had more caries than less well-nourished populations.

Researchers then looked at the mechanism of caries development to discern the role of diet. Cavities are the end result of a process that involves bacteria and sugars in the mouth over time. Streptococcus mutans, bacteria that are normally present in plaque, a very fine film which covers the surfaces of the teeth, metabolize sugar and form acid. When a person consumes sugar in foods or beverages, acid is formed that can dissolve minute amounts of minerals from the enamel surface of the tooth. When this happens repeatedly over time, enough minerals are lost for a cavity to form.

This relationship between sugar consumption and caries was tested in a classic study conducted at Vipeholm, a mental institution in Sweden, and reported in 1954. Although modern ethical standards would preclude a study in which subjects were unable to give informed consent, it remains a landmark piece of research. Residents were assigned to several groups. All ate the standard diet of the institution, but some were given additional sweets in varying quantities and frequency, up to twenty-four sticky toffee candies per day. After five years of observation, the researchers concluded that the stickiness of the sweets and the frequency with which they were consumed, both increasing the amount of time that the bacteria in plaque could produce acid, were more important than the total amount of sugar.

Streptococcus mutans can feed on any carbohydrate, not just sugars. The bacteria make no distinction between "natural" carbohydrates, such as the sugars in fruit, and refined sugars; they make acid from any of them.

Oral bacteria also make acid from sugar in liquids. This can lead to a particular pattern of caries called "baby-bottle caries," which develops when a baby is put to bed with a bottle filled with sugar-containing liquid, including milk. When the baby falls asleep, the liquid pools in the mouth, leading to decay, most often of the front upper teeth.

Since sugar has been shown to play such a significant role in the development of tooth decay, a basic preventive measure is to limit the frequency of sugar consumption. Because it is the action of bacteria on the sugar that is of concern, minimizing the bacteria by careful attention to oral hygiene is equally important. Fluoride, a mineral that is naturally present in water in some areas, has a strong protective effect as well. It binds to the other minerals to become part of the enamel, making the enamel harder and more resistant to decay. It also slows acid formation and promotes repair of places on the teeth where acid has dissolved some of the minerals.

In areas where the naturally occurring level of fluoride in water is low, it is often added during water treatment. Although there have been controversies about water fluoridation, public health authorities, including the American Dental Association, the United States Public Health Service, and the World Health Organization, all support it as a safe and effective preventive measure. One can see its effectiveness in the fact that, although sugar consumption in the United States has been increasing, children have fewer cavities than they had in the years before fluoridation became widespread.

Sugar substitutes are used to produce candies, chewing gum, and beverages that taste sweet without harming the teeth. Chewing gum containing xylitol, one of these alternative sweeteners, has been shown to be protective.

Diet and Periodontal Disease

Gingivitis, or periodontal disease, is the other common dental disorder. The bacteria in dental plaque cause an infection of the gums and structures that hold the teeth in place. The gums become red, swollen, and tender. Food does not play an important role in the development of gum disease, as it does in the formation of caries. Good oral hygiene is the most important preventive measure. A nutritious diet, which supplies generous amounts of vitamins and minerals, can offer some benefit by helping to maintain the immune system's ability to fight the infection.

Dental Status and Eating

The other side of the food and dental health interaction is the importance of healthy dentition in enabling people to eat and enjoy a wide variety of foods. The absence of a significant number of teeth or a condition such as periodontal disease or poorly fitting dentures, which makes chewing uncomfortable, may limit a person's food choices and compromise his or her nutritional status. This problem occurs most frequently in elderly and low-income populations, who are more likely to be at risk for nutritional problems.

Some researchers do not find this effect, possibly because the subjects with poor dentition have chosen nutritious foods that are easy to chew, or because the comparison population ate no better in spite of good dental status. In general, however, poor dental health increases the risk of poor nutritional health. Good dental care can correct most of these problems and enable individuals to enjoy eating a nutritious diet.

Bibliography

American Dental Association web site. Available at www.ada.org.

Burt, B. A., and S. Pai. "Sugar Consumption and Caries Risk: A Systematic Review." Paper presented at the Consensus Development Conference on Diagnosis and Management of Dental Caries throughout Life, Bethesda, Md., March 2001.

FDI Working Group. "Nutrition, Diet, and Oral Health: Report of and FDI Working Group." International Dental Journal 44 (1994): 599–612.

Gustaffson, B. E., C. E. Quensel, L. S. Lanke, et al. "The Vipeholm Dental Caries Study: The Effect of Different Levels of Carbohydrate Intake on Caries Activity in 436 Individuals Observed for Five Years." Acta Odontologica Scandinavica 11 (1954): 232–364.

—Mona R. Sutnick

That branch of the healing arts concerned with the teeth and associated structures of the oral cavity, including prevention, diagnosis and treatment of diseases of the teeth.

• conservative d. — involved with the preservation of natural teeth.
• restorative d. — the repair of defects or injury to teeth.