Kuwait Board Prosthodontics key terms

A guideline stating that the total periodontal ligament area of the abutment teeth supporting a fixed partial denture should equal or exceed that of the teeth being replaced, used to judge whether splinting will overload the abutments.

A tooth, root, or implant that supports and retains a fixed or removable prosthesis. Its periodontal or bone support, angulation, and crown integrity determine how much load it can bear.

The artificial tooth of a fixed partial denture that replaces a missing tooth and restores function and appearance without resting fully on the ridge. Its design affects plaque control and ridge health.

A pontic whose gingival surface is convex and sits in a saucer-shaped depression created in the residual ridge, giving the illusion of a tooth emerging from soft tissue. It demands excellent plaque control.

A pontic design in which the cervical portion overlaps the residual ridge by about one millimetre, hiding the junction while leaving the ridge mostly uncovered and cleanable.

The prepared marginal contour where a restoration meets the tooth, such as a chamfer, shoulder, or knife edge. Its geometry, width, and location influence fit, strength, and periodontal response.

A circumferential band of sound dentine, ideally at least 1.5 to 2 mm in height, retained coronal to the preparation shoulder of an endodontically treated tooth. It resists lever forces and improves restoration survival.

A foundation restoration in which a post is cemented into a prepared root canal and a core is built up to replace lost coronal tooth structure. The post retains the core but does not strengthen the root.

Replacement of missing coronal tooth structure with a material such as composite or amalgam so that a prepared tooth can retain an indirect restoration. Adequate remaining dentine and ferrule matter more than core material.

How closely a restoration's margin conforms to the prepared tooth. Poor adaptation permits microleakage, plaque accumulation, cement dissolution, and secondary caries, and is assessed clinically with explorers and radiographs.

The passage of bacteria, fluids, and ions along the gap between a restoration and tooth structure. It can cause staining, sensitivity, pulpal inflammation, and recurrent caries even when the restoration appears intact.

Caries developing at the margin of an existing restoration, often driven by plaque retention, marginal defects, or leakage. It is a leading reason for replacement of crowns and restorations.

The features of a tooth preparation that prevent the restoration and remaining tooth from fracturing or displacing under occlusal load, including adequate reduction, rounded internal line angles, and sufficient bulk.

The geometric features of a preparation that resist dislodgement of the restoration along its path of insertion, such as taper, surface area, grooves, and boxes. It works together with adhesion and cementation.

The direction in which a rigid prosthesis must travel to seat fully on its abutments. It is determined by the alignment of preparations or abutments and constrains the design of the restoration.

A prepared parallel surface on an abutment tooth that directs the path of insertion of a removable partial denture and provides reciprocation and stabilisation against horizontal forces.

Analysis of diagnostic casts on a surveyor to identify the path of insertion, height of contour, guide planes, and undercuts for a removable partial denture. It guides clasp and framework design.

The components of a removable partial denture that retain and stabilise it, typically including a retentive arm engaging an undercut, a reciprocal arm, and a rest. Design balances retention against harm to abutments.

Prepared tooth surfaces and the framework extensions that sit on them to transmit occlusal forces along the long axis of abutment teeth and to prevent the denture from settling into tissue.

The rigid part of a removable partial denture framework that joins components on both sides of the arch, such as a palatal plate or lingual bar. Rigidity distributes load and prevents torque on abutments.

Progressive loss of alveolar bone and soft tissue height and width after tooth extraction, fastest in the first year and continuing over life. It reduces denture support and stability and is worse with ill-fitting dentures.

The three mechanical requirements of a removable prosthesis: support resists vertical tissue-ward force, stability resists horizontal rotation, and retention resists displacement away from the tissues.

Chronic erythema of denture-bearing mucosa, most often the palate, associated with Candida albicans, continuous denture wear, and poor hygiene. Treatment includes hygiene, tissue rest, and antifungal therapy.

Mechanical and chemical cleaning of removable prostheses and the oral tissues they cover, combined with removing dentures at night, to prevent plaque, stain, candidiasis, and mucosal inflammation.

Direct structural and functional connection between living bone and the surface of a load-bearing implant without intervening soft tissue. It is assessed clinically by absence of mobility and radiographically by bone level.

The interface where the abutment connects to the implant body. Its design and position influence microbial seal, bone remodelling, and prosthetic retrievability, especially in the aesthetic zone.

Use of an abutment narrower than the implant platform, moving the implant-abutment junction medially. It is associated with reduced crestal bone loss and better preservation of peri-implant soft tissue.

Inflammation of peri-implant soft tissue with progressive loss of supporting bone, unlike peri-implant mucositis, which is reversible and confined to soft tissue. Risk factors include plaque, smoking, and history of periodontitis.

A clinically determined maxillomandibular relationship in which the condyles sit in their most anterior, superior position against the articular eminence, independent of tooth contact. It is a reproducible reference for occlusal records.

The complete intercuspation of the opposing teeth regardless of condylar position, also called habitual occlusion. It often differs slightly from centric relation, and this discrepancy is recorded during diagnosis.

Tooth contact that prevents smooth movement of the mandible in excursion or deflects it from a normal path. Interferences may contribute to wear, mobility, and muscle or joint symptoms.

The vertical distance between the maxilla and mandible when the teeth are in contact or the jaws are at rest. It guides complete denture construction and full-mouth rehabilitation.

The difference between the resting vertical dimension and the occlusal vertical dimension, usually about 2 to 4 mm at the incisors. Excessive or insufficient space affects comfort and prosthesis stability.

A group of conditions affecting the temporomandibular joint, masticatory muscles, or both, causing pain, limited movement, or joint sounds. Prosthodontic treatment may provoke or relieve symptoms, so assessment is essential.

Use of a removable occlusal appliance, such as a stabilisation splint, to redistribute occlusal forces, reduce parafunction, and relieve temporomandibular or muscle symptoms. It is usually adjunctive, not curative.

Involuntary grinding or clenching of the teeth, often during sleep, that can cause wear, fractures, implant overload, and muscle discomfort. Management includes appliances, behavioural approaches, and monitoring of restorations.

The fractional change in length of a material per degree of temperature change. A large mismatch between a metal framework and its veneering ceramic can generate stress and contribute to chipping.

The union of a dental ceramic to a metal substructure through chemical, mechanical, and compressive forces. It depends on oxide formation, thermal compatibility, and adequate framework design.

Fracture or loss of a portion of the veneering ceramic on a crown, bridge, or implant restoration. Causes include occlusal overload, framework design, thermal mismatch, and parafunction.

A polycrystalline ceramic used for frameworks, monolithic crowns, and implant components, valued for high strength and toughness. Its opacity, wear of opposing teeth, and ageing behaviour require careful case selection.

A restoration fabricated from a single material throughout, such as full-contour zirconia or lithium disilicate, avoiding a veneering layer and therefore reducing the risk of chipping.

A glass-ceramic with high strength and translucency used for crowns, veneers, and short-span fixed prostheses. Bonding with hydrofluoric acid etching and silane improves retention.

A composite-based luting agent that bonds to tooth structure and to etched or primed restorative surfaces. It offers high retention and low solubility but demands strict moisture control and light access.

An addition-reaction silicone elastomer used for impressions, known for dimensional stability, accuracy, and elastic recovery. It is available in multiple viscosities and is hydrophobic, so dry fields are needed.

Capture of intraoral geometry with an optical scanner to produce a digital model instead of a physical impression. It reduces distortion and storage needs but requires managing soft tissue and scanner accuracy.

Computer-aided design and computer-aided manufacturing of dental restorations, from scan or model through digital design to milling or printing. It affects material choice, fit, and workflow efficiency.

Building objects layer by layer from a digital model, as in stereolithographic printing of models, surgical guides, and provisional or definitive resins. Resolution, orientation, and post-curing affect accuracy.

Subtractive manufacturing in which a block of material is cut by rotating burs to form a restoration. Tool wear, block homogeneity, and milling strategy influence marginal fit and surface quality.

A high-performance polymer used for frameworks, implant abutments, and removable prosthesis components. It is lightweight and biocompatible but has lower rigidity than metal and needs appropriate design.

Subjective dryness of the mouth, often from reduced salivary flow caused by medication, radiotherapy, or autoimmune disease. It increases caries, candidiasis, and denture discomfort and alters impression and bonding protocols.

Concurrent use of multiple medications, common in older adults, which raises the risk of drug interactions and adverse effects such as xerostomia, bleeding, and altered healing relevant to prosthodontic care.

A patient's voluntary agreement to treatment after receiving and understanding information about diagnosis, options, risks, benefits, and alternatives, documented in the record. It is an ongoing process, not a single signature.

Systematic documentation of clinical findings, consent, treatment provided, materials used, and communications. Accurate records support continuity of care and are essential for medico-legal defence.

Infection control measures applied to all patients regardless of known status, including hand hygiene, gloves, eye protection, and safe handling of sharps and contaminated items.

A structured synthesis of all relevant studies answering a focused question, using explicit search, selection, and appraisal methods. It sits near the top of the evidence hierarchy when well conducted.

A study in which participants are randomly allocated to interventions and followed prospectively, reducing selection bias and supporting causal inference. Blinding and adequate sample size strengthen its conclusions.

A ranking of study designs by their susceptibility to bias and strength for causal claims, typically from systematic reviews and randomised trials down to case reports and expert opinion.

The number of patients who must receive an intervention for one additional patient to benefit. It is the reciprocal of the absolute risk reduction and helps translate trial results into clinical decisions.