NDECC key terms

A patient's voluntary agreement to a procedure after receiving and understanding information about its nature, risks, benefits, alternatives, and the consequences of declining. It requires decision-making capacity and may be withdrawn at any time.

A patient's ability to understand relevant information, appreciate the consequences of a decision, reason through options, and communicate a choice. Capacity is decision-specific and assessed clinically rather than by diagnosis alone.

The standard used when a patient lacks capacity, requiring decisions that promote that person's welfare, weighing benefits, burdens, and previously expressed wishes. It differs from substituted judgment, which applies the patient's own known preferences.

A risk or complication that a reasonable person in the patient's position would consider significant when deciding whether to accept treatment, including low-probability but serious harms. Such risks must be disclosed during consent discussions.

A collaborative process in which clinician and patient exchange evidence and values to reach a mutually agreed treatment choice. It combines professional expertise with patient preferences and is central to patient-centred communication.

The professional duty to protect patient information from unauthorised disclosure. It may be breached only with consent or when required or permitted by law, such as for serious public safety concerns.

A ranked list of plausible conditions that could explain a patient's signs and symptoms, generated from history and examination. Each candidate is then tested or excluded through further investigation to reach a working diagnosis.

The provisional explanation of a patient's problem that guides initial management while uncertainty remains. It is revised as new findings emerge and differs from a definitive diagnosis confirmed by tests or response to treatment.

The proportion of people who truly have a condition and are correctly identified by a test as positive. Highly sensitive tests are useful for ruling out disease when the result is negative.

The proportion of people without a condition who are correctly identified by a test as negative. Highly specific tests are useful for ruling in disease when the result is positive.

The probability that a positive or negative test result correctly reflects the presence or absence of disease in a given population. Predictive values depend on disease prevalence, unlike sensitivity and specificity.

A ratio comparing how likely a test result is in people with disease versus those without. It allows a clinician to update the pre-test probability of disease to a post-test probability.

The number of patients who must receive a treatment for one additional patient to benefit, calculated as the reciprocal of the absolute risk reduction. Lower values indicate a more effective intervention.

The arithmetic difference in event rates between a control group and a treated group. It reflects the actual clinical impact of an intervention, unlike relative risk reduction, which can appear large when baseline risk is low.

A range of values, calculated from sample data, that is likely to contain the true population effect with a stated probability, usually 95 percent. It conveys both precision and statistical significance.

A structured synthesis that answers a focused question by comprehensively searching for, appraising, and combining all relevant studies using explicit, reproducible methods. It sits near the top of the evidence hierarchy.

An experimental study in which participants are randomly allocated to interventions, minimising selection bias and allowing causal inference. Blinding and intention-to-treat analysis further strengthen its validity.

Distortion of an observed exposure-outcome association by a third variable linked to both, creating a spurious or exaggerated relationship. Randomisation, restriction, matching, and statistical adjustment help control it.

Analysing participants according to the group to which they were originally allocated, regardless of adherence. It preserves randomisation benefits and gives a realistic estimate of effectiveness in practice.

The tendency for studies with positive or statistically significant findings to be published more readily than negative ones, distorting the evidence base. Funnel plots and trial registries help detect and reduce it.

Classification of the dental pulp's status, such as normal, reversible pulpitis, symptomatic or asymptomatic irreversible pulpitis, or necrotic, based on history, testing, and clinical findings. It guides endodontic treatment decisions.

Gentle tapping of a tooth to assess whether the periodontal ligament is inflamed, typically indicating apical periodontitis or acute periapical pathology. Tenderness to percussion suggests inflammation extending beyond the root apex.

The distance from a reproducible coronal reference point to the intended apical preparation limit within the root canal. Accurate determination, often with electronic apex locators and radiographs, prevents short or over-instrumentation.

Three-dimensional radiographic imaging using a cone-shaped X-ray beam to reconstruct maxillofacial anatomy at lower dose than conventional CT. It aids diagnosis of complex root canal anatomy, fractures, and implant sites.

A narrow channel through bone and soft tissue that drains an abscess or chronic infection to a surface, often appearing as a parulis or gumboil. Tracking the tract can identify the causative tooth.

The distance from the cemento-enamel junction to the base of the periodontal sulcus or pocket, reflecting cumulative periodontal destruction. It is a key measure for diagnosing and staging periodontitis.

The measured distance from the gingival margin to the base of the periodontal pocket, recorded with a calibrated probe. It can overstate attachment loss when the gingival margin is coronal to the cemento-enamel junction.

A structured evaluation of patient-level factors such as smoking, glycaemic control, plaque levels, and history of disease progression to estimate future periodontal risk and tailor maintenance intervals.

A technique in which a probe is placed through an extraction socket or around a tooth to assess bone contours, dehiscence, or fenestration defects. It helps evaluate ridge anatomy and periodontal defects before planning treatment.

A group of conditions affecting the temporomandibular joint, masticatory muscles, or associated structures, causing pain, limited movement, or joint sounds. Management often begins with conservative, reversible measures.

A neuropathic pain disorder producing brief, severe, electric shock-like facial pain in the distribution of the trigeminal nerve, often triggered by touch, chewing, or cold. It is managed medically, commonly with carbamazepine.

A removable acrylic or resin appliance worn over the teeth to redistribute occlusal forces and reduce parafunctional loading. It is used in management of bruxism and some temporomandibular disorders.

The relationship of the maxilla and mandible when the teeth are in maximal intercuspation, determining facial height and prosthetic space. It must be preserved or carefully altered during extensive restorative and prosthodontic treatment.

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 complete dentures and occlusal rehabilitation.

The encircling of a prepared tooth by a cast restoration or crown extending at least 1.5 to 2 millimetres beyond the core, which resists fracture and improves the prognosis of endodontically treated teeth.

A restorative foundation placed in a root canal space to retain a core and subsequent crown when insufficient coronal tooth structure remains. Retention and remaining dentine thickness determine its success.

The removal of a tissue sample for histopathological examination to establish or confirm a diagnosis. It is indicated for persistent lesions, suspected malignancy, or any unexplained oral mucosal abnormality.

A clinical presentation of the oral mucosa with an increased risk of developing squamous cell carcinoma, including leukoplakia, erythroplakia, and oral submucous fibrosis. Biopsy and surveillance are often required.

A clinical feature or history finding suggesting serious pathology and prompting urgent investigation or referral, such as unexplained weight loss, persistent ulceration, or progressive neurological deficit.

The routine cleaning of hands with soap and water or alcohol-based rub at defined clinical moments to prevent transmission of microorganisms. It is the single most effective measure for reducing healthcare-associated infection.

Barrier items such as gloves, masks, eye protection, and gowns worn to protect clinicians and patients from exposure to bloodborne pathogens and other hazards. It must be removed and disposed of safely after use.

A validated process that destroys all microorganisms, including bacterial spores, on reusable instruments, commonly by autoclaving. It is distinguished from disinfection, which reduces but does not eliminate all organisms.