plaque

(plăk)
n.

1. A flat plate, slab, or disk that is ornamented or engraved for mounting, as on a wall for decoration or on a monument for information.
2. A small pin or brooch worn as an ornament or a badge of membership.
3. 1. Pathology. A small disk-shaped formation or growth; a patch.
   2. A deposit of fatty material on the inner lining of an arterial wall, characteristic of atherosclerosis.
   3. A scaly patch formed on the skin by psoriasis.
   4. A film of mucus and bacteria on a tooth surface.
   5. A clear, often round patch of lysed cells in an otherwise opaque layer of a bacteria or cell culture.

[French, from Old French, metal plate, perhaps from Middle Dutch placke, disk, patch.]

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1. Dental plaque is a layer of bacteria in an organic matrix on the surface of teeth, especially around the neck of each tooth. May lead to development of gingivitis, periodontal disease, and caries.

2. Atherosclerotic plaque is the development of fatty streaks in the walls of blood vessels; see also atherosclerosis.

Dental plaque is a biofilm that forms naturally on the tooth surface. It consists of a diverse microbial community embedded in a polymer matrix of bacterial and salivary origin. Because environmental conditions vary from place to place within the oral cavity, each tooth site with plaque represents its own distinct ecosystem, and the dominant microbial composition at each site depends on the outcome of numerous host-microbe and microbemicrobe interactions. Initial bacterial colonizers quickly become established on a clean tooth surface, and a pattern of subsequent bacterial succession has been identified. If left undisturbed, plaque reaches a maximum bulk after about seven days. Plaque deposition begins supragingivally—on the visible part of the tooth above the gum line—and if left undisturbed can progress subgingivally—into the crevice between the gum and the tooth. Microbial interactions usually keep the bacterial composition of plaque fairly stable, but when this homeostasis breaks down, the shifts in microbial balance can trigger the initiation of dental caries (tooth decay) or gingivitis (gum inflammation). Few bacteria can be isolated from around healthy gum tissue, although with gingivitis there is a considerable increase in the number and complexity of bacteria as the lesion develops. Subgingival plaque, if left undisturbed, can become a calcified matrix (calculus, or tartar) that can harbor harmful bacteria. Not surprisingly, subgingival calculus is closely associated with periodontal diseases. Specifically, Porphyromonas gingivalis and Bacteroides forsythus in subgingival plaque had been associated with both periodontal inflammation and bone loss.

Although dental plaque is commonly depicted in commercial advertising as the cause of both caries and periodontitis, dental plaque also benefits the host by helping to prevent intra-oral colonization by exogenous species. Plaque is also a repository for fluoride and other minerals that serve both to inhibit the demineralization of dental enamel—the first step in the development of a cavity—and to promote remineralization of early lesions. The fact that caries is initiated by a drop in plaque pH, following the fermentation of simple carbohydrates by certain bacteria resident in plaque, further exemplifies plaque's delicate ecology. Controlled plaque is beneficial, uncontrolled plaque can be harmful.

Prevention of plaque-related disease is geared toward plaque control rather than eradication. The goal in preventing periodontitis (diseases of the supporting structures of the tooth) is to prevent fresh plaque from becoming established enough to permit the growth of pathogenic bacteria. This goal is best achieved by thorough toothbrushing at least once per day with a fluoridecontaining toothpaste, plus consistent professional prophylactic care. So long as plaque remains supragingival, it can be controlled by mechanical or chemotherapeutic means. Once plaque becomes established subgingivally, however, an individual cannot remove it and professional intervention is necessary. Carrying out personal oral hygiene with a fluoride-containing toothpaste helps maintain high fluoride levels in plaque and thus inhibits the development of caries.

(SEE ALSO: Caries Prevention; Gingivitis; Oral Health; Primary Prevention)

Bibliography

Zambon, J. J. (1997). "Principles of Evaluation of the Diagnostic Value of Subgingival Bacteria." Annals of Periodontology 2:138–148.

— BRIAN A. BURT

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(Fr.)

‘Laid down’: an instruction to perform the notes of a chord simultaneously rather than successively.

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A tablet that is affixed to the surface of a wall or set into a wall; often inscribed to commemorate a special event or to serve as a memorial.

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Strands of fibrous tissue that attach to the inside of blood vessels. Plaque formation contributes to the development of atherosclerosis, which may lead to a heart attack or a stroke. Its rate of development depends on heredity, diet, and other aspects of lifestyle; regular aerobic exercise may reduce plaque formation.

(plak)

A thin film composed of bacteria, mucus, and food particles that forms on the surfaces of teeth. Plaque contributes to tooth decay and gum disease. Plaque also refers to a combination of cholesterol and lipids that can accumulate on the inside of arteries, causing atherosclerosis.

IN BRIEF: A flat metal plate or tablet that is inscribed and used for decoration or as a memorial. Also: A thin film that forms on the teeth and hardens into tartar if not removed.

Abraham Lincoln's words, "To care for him who shall have borne the battle and for his widow, and his orphan," appear on a plaque on the Veterans Administration building in Washington D.C.

LearnThatWord.com is a free vocabulary and spelling program where you only pay for results!

1. any small disk-like object, patch, or zone.
2. a macroscopic or microscopic rounded clear zone in a layer of cells or bacterial lawn that results from the killing or lysis of adjacent cells by the action of a virus or other agent.
3. 
   (a) (a patch of) fibrous or lipid material on the inner surface of an artery.
   
   (b) an area of tissue degeneration with distinctive histological features characteristic of certain (especially neurological) diseases, e.g. kuru, multiple sclerosis.
   
   (c) a deposit of β-amyloid, numbers of which are typically found in the brains of patients with Alzheimer's disease.
   
4. (a patch of) deposit closely adherent to the surface of a tooth that contains a mixed microbial flora and is composed largely of extracellular bacterial polysaccharide.

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Next:	plaque-lift, plasm+, plasma

1. any patch or flat area.
2. a clear area of cell lysis caused by viral replication on a cell monolayer.

• amniotic p. — small, 1 to 2 inch diameter, poxlike lesion on the inside of the amnion. Constant on the bovine amnion during the middle trimester and causes no problems.
• annular p. — seen in equine lupus erythematosus panniculitis.
• p. assay — a method of quantifying the number of infectious units by inoculating serial dilutions of a viral suspension on a cell culture monolayer, overlaying with a medium containing agarose and after several days incubation, counting the number of plaques formed; recorded as plaque forming units/ml.
• atheromatous p. — a deposit of predominantly fatty material in the lining of blood vessels occurring in atherosclerosis.
• bacterial p., dental p. — a mass adhering to the enamel surface of a tooth, composed of a mixed colony of bacteria in an intercellular matrix of bacterial and salivary polymers and remnants of epithelial cells and leukocytes. It may cause caries, dental calculi and periodontal disease.
• cutaneous p. — an elevated, solid structure without a necrotic center, up to 1 to 2 inch diameter with an unbroken surface.
• drug p. — cutaneous, subcutaneous or subconjunctival deposits formed as a result of injection of some drugs, particularly repository steroid preparations. May be unsightly and a cause of conjunctivitis.
• ear p. — see ear plaque.
• eosinophilic p. — see eosinophilic plaque.
• p.-forming cells — see plaque assay (above).
• p.-forming count — the number of plaques formed in the plaque assay.
• senile p. — described in the brain of old dogs.
• siderotic p. — nodules observed as dry, yellow encrustations on the splenic capsule of old dogs.

n
plak

A flat plate or tablet.

For a list of words related to plaque, see:

• Signs and Symptoms - plaque: sticky, colorless mixture of saliva, bacteria, and carbohydrates on surface of teeth that causes tartar and caries

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See words rhyming with "plaque."

  See crossword solutions for the clue Plaque.

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
n. - platte, mindetavl, plak

Nederlands (Dutch)
(gedenk)plaat, tandaanslag, huidvlek

Français (French)
n. - plaque, (Dent) plaque dentaire

Deutsch (German)
n. - Plaque, Zahnbelag, Plakette

Ελληνική (Greek)
n. - πλάκα (αναμνηστική ή τιμητική), οδοντική πλάκα (κν. πέτρα)

Italiano (Italian)
placca batterica

Português (Portuguese)
n. - placa (f), placa bacteriana (f), condecoração (f)

Русский (Russian)
табличка, рос бактерии на зубах, бляха

Español (Spanish)
n. - placa, sarro

Svenska (Swedish)
n. - (minnes)tavla, plåt, platta, tandbeläggning

中文（简体）(Chinese (Simplified))
匾, 名牌, 饰板

中文（繁體）(Chinese (Traditional))
n. - 匾, 名牌, 飾板

한국어 (Korean)
n. - 액자, (훈자의 일종) 소판꼴의 브로치

日本語 (Japanese)
n. - 飾り額, 記念額, 歯垢, 記念銘板

العربيه (Arabic)
‏(الاسم) دبوس, زيني, بروش, صفيحه معدنيه‏

עברית (Hebrew)
n. - ‮לוחית, לוח, טבלת-זיכרון על קיר בניין, משקע עם חידקים על שן, פריחה בעור, פצע סיבי בטרשת-עורקים, תג-דרגה במסדר של כבוד‬

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