PMC Dentistry Licensure key terms

The basic structural unit of enamel, a tightly packed bundle of hydroxyapatite crystallites running from the dentinoenamel junction toward the surface, usually with a slight change in direction at the surface.

The scalloped interface where enamel meets dentine, formed by the initial mineralisation pattern of ameloblasts and odontoblasts; its irregular shape increases mechanical interlocking between the two hard tissues.

A narrow channel running through dentine from the pulp to the dentinoenamel junction, containing an odontoblast process and fluid; its patency explains dentine sensitivity and pulpal response to caries.

The process by which ameloblasts secrete and mineralise enamel matrix in stages, starting at the dentinoenamel junction and proceeding outward; the cells are lost after eruption, so enamel cannot regenerate.

A thin mineralised tissue covering the root surface, produced by cementoblasts; it anchors periodontal ligament fibres and remodels continuously, unlike enamel, which does not form after eruption.

The fibrous connective tissue between root cementum and alveolar bone that suspends the tooth, transmits occlusal force, and provides proprioception and remodelling capacity.

The portion of maxilla and mandible that supports the tooth roots, comprising the alveolar process and its socket lining; it depends on the presence of teeth and resorbs after extraction.

The ophthalmic, maxillary, and mandibular branches of the fifth cranial nerve; V2 and V3 supply sensation to the teeth, periodontium, and oral mucosa, and V3 also carries motor fibres to the muscles of mastication.

A branch of the mandibular division of the trigeminal nerve that enters the mandibular canal to supply the mandibular teeth and exits at the mental foramen as the mental nerve.

A small space behind the maxilla containing the maxillary nerve and its branches, the pterygopalatine ganglion, and vessels; it communicates with the orbit, nasal cavity, palate, and infratemporal fossa.

A thin protein film formed on tooth and mucosal surfaces by selective adsorption of salivary glycoproteins; it lubricates, limits demineralisation, and provides receptors for bacterial adhesion.

An organised community of bacteria embedded in a polysaccharide matrix attached to tooth or other surfaces; its metabolism of dietary sugars produces acids that cause caries and drives periodontal inflammation.

A multifactorial, sugar-dependent, biofilm-mediated disease causing progressive demineralisation and destruction of tooth hard tissues, resulting in cavitation if the balance between demineralisation and remineralisation is not restored.

The return of calcium and phosphate ions into partially demineralised enamel or dentine, restoring mineral and reducing lesion progression; it is promoted by fluoride, saliva, and reduced sugar exposure.

A developmental enamel defect caused by excessive fluoride intake during tooth formation, appearing as diffuse opacities that range from white flecks to pitting; severity depends on dose and timing.

A concentrated topical fluoride preparation applied to tooth surfaces to prevent caries by enhancing remineralisation and inhibiting demineralisation; its small volume minimises the risk of ingestion.

The lowest concentration of an antimicrobial agent that prevents visible growth of a microorganism under defined conditions; it guides antibiotic choice and susceptibility reporting.

The ability of microorganisms to survive and grow despite exposure to antimicrobial drugs, arising through genetic mutation or acquired resistance genes and worsened by unnecessary or incomplete prescribing.

Administration of antibiotics before a procedure to prevent infection, such as infective endocarditis in high-risk cardiac patients or infection in severely immunocompromised patients; it is not a substitute for asepsis.

A drug that reversibly blocks sodium channels in nerve membranes, preventing impulse conduction and producing regional loss of sensation without loss of consciousness.

An agent such as adrenaline added to a local anaesthetic solution to reduce local blood flow, prolong anaesthesia, and limit systemic absorption; it requires caution in patients with cardiovascular disease.

The upper limit of a drug calculated for a patient, usually per kilogram of body weight, that should not be exceeded in a single appointment to avoid systemic toxicity.

Inflammation of the dental pulp, usually caused by caries, trauma, or restorative procedures; it may be reversible or irreversible and presents with pain that may be provoked or spontaneous.

Inflammation of the tissues around the root apex, typically caused by infection from a necrotic pulp; it may be acute and painful or chronic and asymptomatic with a periapical radiolucency.

The cleaning, shaping, disinfection, and obturation of the root canal system to eliminate infection and retain a tooth that would otherwise require extraction or cause periapical disease.

The distance from a coronal reference point to the apical limit of instrumentation, usually the apical constriction, determined by radiographs and electronic apex locators to avoid short or over-instrumentation.

A layer of debris, cut dentine, and bacteria produced on dentine during instrumentation; it reduces dentine permeability and must be removed or modified for bonding and disinfection.

The interdiffusion zone formed when resin infiltrates demineralised dentine and polymerises around collagen fibres, providing micromechanical retention for adhesive restorations.

The reduction in volume that occurs when resin composite sets, producing stress at the tooth-restoration interface that may cause marginal gaps, postoperative sensitivity, or recurrent caries.

A restorative material made by mixing silver-tin-copper alloy powder with mercury; it is strong and durable but requires sound tooth support and is being phased down under the Minamata Convention.

The vertical distance between the maxilla and mandible when the teeth or occlusion rims are in contact; it guides the design of dentures and the restoration of worn dentition.

A maxillomandibular relationship in which the condyles articulate with the thinnest avascular portion of their discs, independent of tooth contact; it is a reproducible reference for occlusal records.

A removable prosthesis that replaces all teeth and associated structures in one arch, relying on retention, stability, and support from the residual ridge and mucosa.

A chronic inflammatory disease of the supporting tissues caused by plaque biofilm, characterised by loss of attachment and alveolar bone, with pocket formation and possible tooth loss.

The mechanical removal of plaque and calculus from tooth surfaces and root surfaces to control periodontal inflammation; it is the basis of non-surgical periodontal therapy.

The portion of gingiva firmly bound to the underlying periosteum and cementum, extending from the free gingival groove to the mucogingival junction; it resists functional stress.

The set of measures, including hand hygiene, personal protective equipment, instrument sterilisation, and safe sharps handling, that prevents transmission of pathogens between patients and staff.

The destruction or removal of all microorganisms, including bacterial spores, from an object; in dentistry it is achieved mainly by autoclaving instruments after cleaning and packaging.