NDEB AFK key terms

The highly mineralized, acellular outer layer covering the crown of a tooth. It is formed by ameloblasts before eruption and, once mature, cannot regenerate; its high hydroxyapatite content makes it the hardest tissue in the body.

The mineralized tissue beneath enamel and cementum that forms most of the tooth's bulk. It contains microscopic tubules housing odontoblast processes and is softer than enamel but capable of continuous, slow formation throughout life.

A thin mineralized tissue covering the tooth root. Periodontal ligament fibres insert into it, anchoring the tooth to bone; it is formed by cementoblasts and shows slow, continuous apposition over life.

The ligament of collagen fibre bundles that connects cementum to alveolar bone. It suspends the tooth in its socket, absorbs occlusal forces, and carries proprioceptive nerve endings that help control biting force.

A tall, columnar cell lining the inner surface of the pulp. It secretes predentin, which mineralizes into dentin, and its process extends into a dentinal tubule; the cells persist for the life of the tooth.

A cell of ectodermal origin that secretes and mineralizes enamel matrix during tooth development. Ameloblasts retreat outward as enamel thickens and are lost when the tooth erupts, so enamel cannot be replaced.

The fifth cranial nerve, which carries sensation from the face, teeth and oral mucosa through its ophthalmic, maxillary and mandibular divisions. Its mandibular division also supplies motor fibres to the muscles of mastication.

A band of non-keratinized epithelial cells that attaches the gingiva to the tooth surface at the base of the sulcus. It forms the soft-tissue seal protecting underlying periodontal tissues from oral bacteria.

The part of the maxilla and mandible that forms the tooth sockets and supports the teeth through the periodontal ligament. It develops with eruption and resorbs after tooth loss, altering ridge shape.

The largest salivary gland, located in front of the ear and draining through Stensen's duct opposite the upper second molar. It secretes mainly serous, amylase-rich saliva and is the most common site of salivary tumours.

A rapid, self-propagating change in membrane potential caused by sequential opening of ion channels. In nerve and muscle it transmits signals along the cell and triggers processes such as neurotransmitter release or muscle contraction.

A large multinucleated cell derived from haematopoietic precursors that resorbs bone by secreting acid and enzymes. It works with osteoblasts in bone remodelling and is central to orthodontic tooth movement and socket healing.

A bacterial disease in which acids from fermentable carbohydrates demineralize enamel and dentin. It progresses through reversible white-spot lesions to cavitation and, if untreated, pulp involvement.

Reversible inflammation of the gingiva caused by plaque biofilm, producing redness, swelling and bleeding on probing. There is no loss of periodontal attachment, and it resolves with effective plaque control.

Inflammation of the periodontal tissues caused by plaque biofilm that leads to loss of attachment and alveolar bone. It is diagnosed by probing depths, clinical attachment loss and bleeding, and is a major cause of tooth loss.

Inflammation of the dental pulp, usually from caries or trauma. It may be reversible, with sharp pain to stimuli, or irreversible, with spontaneous or lingering pain that does not resolve and usually requires root canal treatment.

Inflammation around the root apex caused by infection in the root canal system. It appears as a periapical radiolucency and may be symptomatic or asymptomatic; treatment is root canal therapy or extraction.

Loss of tooth substance from tooth-to-tooth contact during chewing or parafunction. It produces flattened, polished wear facets on occlusal and incisal surfaces and is distinct from abrasion and erosion.

Loss of dental hard tissue by chemical dissolution from acids not produced by oral bacteria, such as dietary acids or gastric reflux. It causes smooth, cupped or scooped surfaces, often on palatal or cervical areas.

A dental restorative material made by mixing silver-tin-copper alloy powder with mercury. It is strong, durable and inexpensive but non-aesthetic, and its use is declining for environmental and aesthetic reasons.

A tooth-coloured restorative material of resin matrix filled with glass or ceramic particles, bonded to tooth structure. It is aesthetic and allows conservative preparation but is technique-sensitive and can wear or stain over time.

The distance from a coronal reference point to the root canal's apical constriction, determined by radiographs and electronic apex locators. It guides instrumentation and obturation so the canal is cleaned without damaging periapical tissues.

A malocclusion in which the lower first molar is positioned distal to the upper first molar, usually with a prominent overjet. It is subdivided into division 1, with proclined upper incisors, and division 2, with retroclined incisors.

Also called dry socket; severe pain from loss of the blood clot after extraction, exposing bone. It occurs a few days after surgery, most often with mandibular molars, and is treated by irrigation and dressing.

Exposed bone persisting for more than eight weeks in a patient taking antiresorptive or antiangiogenic drugs, with no history of radiotherapy to the jaw. It presents with pain, infection and non-healing sockets after extraction.

A latex or non-latex sheet stretched over a frame and clamped to isolate teeth during treatment. It keeps the field dry and clean, protects the airway from debris and improves access and infection control.

The proportion of a population that has a condition at a given point or period in time. It reflects the total burden of disease and is influenced by both incidence and the duration of the condition.

The number of new cases of a condition arising in a defined population over a specified period. It measures the risk of developing disease and is used to study causes and evaluate prevention.

An index that counts decayed, missing and filled teeth to summarize caries experience. The score is cumulative and widely used in surveys, though it does not capture the severity of individual lesions.

The proportion of people who truly have a condition and are correctly identified as positive by a test. A highly sensitive test has few false negatives, so it is useful for ruling out disease.

The proportion of people who do not have a condition and are correctly identified as negative by a test. A highly specific test has few false positives, so it is useful for confirming disease.

A study in which participants are randomly allocated to intervention or control groups and followed prospectively. Randomization balances known and unknown confounders, making it the strongest design for testing treatment effectiveness.

The controlled addition of fluoride to a public water supply to reach a level that prevents caries. It reduces decay across the whole population regardless of individual behaviour or access to dental care.

A behavioural theory explaining health action by perceived susceptibility, severity, benefits and barriers, plus cues to action and self-efficacy. It is used to design preventive messages, though it explains individual decisions better than social influences.

A person-centred counselling style that helps patients resolve ambivalence about behaviour change by exploring their own reasons and values. It uses open questions, reflective listening and affirmation rather than advice or confrontation.

A patient's voluntary agreement to treatment after receiving and understanding information about the diagnosis, proposed procedure, alternatives, risks, benefits and consequences of refusing. It requires capacity and can be withdrawn at any time.

The conditions in which people are born, grow, work and age, including income, education, housing and social support. They shape exposure to risk factors and access to care, explaining inequalities in oral health.