Dental Hygienist Licensing Exam key terms

A thin band of nonkeratinized epithelial cells that attaches the gingiva to the tooth surface at the base of the sulcus, forming the soft tissue seal against bacterial invasion.

The shallow V-shaped space between the free gingival margin and the tooth surface, bounded at its base by the junctional epithelium; healthy depth is typically one to three millimeters.

The network of collagen fibers and connective tissue that anchors the tooth root to the alveolar bone, absorbs occlusal forces, and carries blood vessels and nerves.

The line where the enamel of the crown meets the cementum of the root; it marks the cervical area and is a common site for recession, abrasion, and root caries.

The portion of the maxilla and mandible that forms the tooth sockets and supports the roots; it remodels continuously in response to tooth loading and is lost in periodontitis.

A structured, adherent community of bacteria embedded in a polysaccharide matrix on tooth and restoration surfaces; it is the primary etiologic factor in caries and periodontal disease.

Mineralized plaque biofilm that forms on teeth and dental prostheses; it is covered by living plaque, cannot be removed by brushing, and requires professional scaling.

A cariogenic bacterium that colonizes tooth surfaces, metabolizes sugars into acid, and produces glucans that help plaque adhere; a key organism in dental caries.

The pH level at which saliva and plaque fluid become unsaturated with respect to tooth mineral, roughly 5.5 for enamel, causing net demineralization to begin.

The process by which calcium and phosphate ions from saliva and fluoride products re-enter demineralized enamel or dentin, restoring mineral content and reducing caries progression.

A pathologically deepened gingival sulcus caused by migration of the junctional epithelium along the root, measured clinically as probing depth and a sign of attachment loss.

The distance from the cementoenamel junction to the base of the periodontal pocket; it measures cumulative destruction of the periodontal attachment apparatus.

The subjective sensation of dry mouth, often caused by reduced salivary flow from medications, radiation, or autoimmune disease, that raises caries and candidiasis risk.

A class of drugs that inhibit bone resorption and are used for osteoporosis and cancer-related bone disease; they are linked to medication-related osteonecrosis of the jaw after invasive dental care.

The removal of plaque and calculus from coronal and root surfaces with hand or powered instruments, aimed at restoring gingival health rather than producing a smooth root.

A nonsurgical periodontal therapy that removes deposits from the crown and root and smooths roughened cementum, usually performed by quadrant under local anesthesia.

An area-specific hand instrument with a curved, offset blade and only one cutting edge, designed to adapt to a particular tooth surface for subgingival calculus removal.

A hand instrument with a pointed tip and two cutting edges on a straight or curved shank, used for supragingival calculus and heavy deposits above the gingival margin.

A calibrated hand instrument marked in millimeter increments used to measure sulcus or pocket depth, attachment loss, and bleeding on probing around each tooth.

A powered device that uses high-frequency vibration of a tip, with water irrigation, to disrupt and flush plaque and calculus from tooth surfaces.

A resin or glass ionomer coating bonded into the pits and fissures of caries-susceptible teeth to block bacteria and food from retentive surfaces.

A high-concentration fluoride lacquer painted on tooth surfaces that adheres to saliva and releases fluoride over time; used for caries prevention and dentin hypersensitivity.

An intraoral image showing the crowns of maxillary and mandibular posterior teeth together with crestal bone; used to detect interproximal caries and bone loss.

The radiation safety principle of keeping exposures As Low As Reasonably Achievable, using fast film or digital sensors, collimation, and proper technique.

Infection control practices, including gloves, masks, eye protection, and hand hygiene, applied to every patient because bloodborne status cannot be assumed.

A structured evaluation of disease indicators and risk factors such as diet, fluoride exposure, saliva, and past caries, used to plan preventive and restorative care.

The identification of actual or potential oral health problems that fall within the scope of dental hygiene care, based on assessment data and used to plan interventions.

Injection of anesthetic solution near the terminal nerve endings of a tooth to numb a small area, commonly used in the maxilla and for mandibular anterior teeth.

The number of new cases of a disease that develop in a defined population during a specified time period; it measures risk and is used in cohort studies.

The total number of existing cases of a disease in a population at a given point or period, expressed as a proportion; it reflects burden rather than risk.

A count of decayed, missing, and filled permanent teeth per person, used to summarize coronal caries experience in populations and to compare groups over time.

Sensitivity is the proportion of truly diseased people a test correctly identifies; specificity is the proportion of truly healthy people it correctly classifies as disease-free.

An experimental study in which participants are randomly assigned to treatment or control groups, reducing bias and providing the strongest evidence for cause and effect.

Adjusting the fluoride concentration of a public water supply to an optimal level for caries prevention, a population-wide measure that benefits all residents regardless of individual behavior.

A behavior-change framework holding that preventive action depends on perceived susceptibility, severity, benefits, barriers, self-efficacy, and a cue to act.

A screening index that scores periodontal conditions of index teeth using a special probe, recording bleeding, calculus, and pocket depth to describe periodontal status in groups.