National Board Dental Examination / Integrated National Board Dental Examination (INBDE) Restorative, Endodontic, and Prosthodontic Dentistry Syllabus

Differentiate resistance form and retention form in cavity preparation.

Resistance form enables the restoration and tooth to withstand occlusal forces without fracture (e.g., flat pulpal floor, rounded internal line angles). Retention form prevents displacement/dislodgement of the restoration (e.g., parallel walls, dovetails, undercuts).

How does cavity preparation design differ between amalgam and composite restorations?

Amalgam requires mechanical retention (undercuts, 90-degree cavosurface margins, defined internal form) since it doesn't bond. Composite allows more conservative, retentive bonding so preparations follow caries extent with beveled enamel margins and no need for undercuts.

What is the difference between affected and infected dentin in caries excavation?

Infected dentin is irreversibly demineralized, bacteria-laden, and soft - it must be removed. Affected dentin is demineralized but not bacterially invaded, remineralizable, and should be preserved especially near the pulp.

What is the purpose of pulp protection, and when are liners vs bases used?

To protect pulp from thermal, chemical, and bacterial irritation. Liners (thin, e.g., calcium hydroxide, RMGI) seal/stimulate reparative dentin in deep prep; bases (thicker) provide thermal insulation and mechanical support under restorations.

Why is calcium hydroxide used as a pulpal liner in deep cavities?

Its high pH (~12) is antibacterial and stimulates the formation of reparative (tertiary) dentin and a dentin bridge, protecting the pulp in deep or near-exposure preparations (direct/indirect pulp cap).

What is the proper finishing and polishing sequence for composite restorations, and why polish?

Gross contour with fine diamonds/carbides, then finishing discs (coarse to fine), rubber points/cups, and polishing pastes. Polishing reduces plaque retention, staining, and wear and improves esthetics and marginal integrity.

Why is rubber dam isolation considered the gold standard, especially for endodontics?

It provides a dry, clean field; improves visibility and moisture control (critical for bonding); protects the patient from aspiration/ingestion of instruments and irrigants; and prevents salivary/bacterial contamination of the canal system.

What is the purpose of a matrix band and wedge in Class II restorations?

The matrix band restores the missing proximal wall to allow condensation and proper contour/contact. The wedge adapts the matrix at the gingival margin, prevents overhangs, and provides slight tooth separation to ensure a tight contact.

Differentiate reversible pulpitis from irreversible pulpitis clinically.

Reversible: short, sharp pain to stimuli (cold) that resolves quickly when stimulus removed; pulp can heal. Irreversible: spontaneous, lingering pain (often to heat, relieved by cold in late stages); requires root canal or extraction.

What are the responses to pulp vitality (cold/EPT) testing in normal, necrotic, and irreversibly inflamed pulps?

Normal: mild, non-lingering response. Reversible pulpitis: exaggerated but non-lingering. Irreversible pulpitis: exaggerated, lingering response. Necrotic pulp: no response to thermal or electric pulp testing.

Differentiate symptomatic apical periodontitis, acute apical abscess, and chronic apical abscess.

Symptomatic apical periodontitis: painful periradicular inflammation, tender to percussion. Acute apical abscess: rapid onset, severe pain, swelling, pus. Chronic apical abscess: gradual, often asymptomatic with a draining sinus tract.

What does pain to percussion versus pain to palpation indicate in endodontic diagnosis?

Pain to percussion indicates inflammation of the periodontal ligament (periradicular involvement). Pain to palpation indicates inflammation has extended through cortical bone into surrounding soft tissues/periapex.

What are the principles/objectives of endodontic access cavity preparation?

Achieve straight-line access to canal orifices and apex, remove the entire pulp chamber roof, conserve sound tooth structure, locate all canals, and avoid gouging/perforation. Outline form is dictated by pulp chamber anatomy.

What is the typical canal anatomy of maxillary first molars and the clinically important extra canal?

Three roots with usually 4 canals: mesiobuccal (MB1 and frequently MB2), distobuccal, and palatal. The MB2 canal is commonly missed and is a frequent cause of endodontic failure.

What is working length and how is it determined?

Working length is the distance from a coronal reference point to the apical termination of preparation (ideally ~0.5-1 mm short of the radiographic apex, at the apical constriction). Determined by apex locator and confirmed radiographically.

What are the goals of cleaning and shaping (biomechanical preparation) of the root canal?

Remove pulp tissue, bacteria, and debris; shape canal into a continuous tapering funnel (apex narrowest) maintaining original canal path; keep apical foramen small; and create space for irrigation and obturation.

Why is sodium hypochlorite (NaOCl) the primary endodontic irrigant, and what is EDTA used for?

NaOCl dissolves organic tissue (necrotic pulp) and is antibacterial. EDTA is a chelating agent that removes the inorganic smear layer and lubricates/softens canal walls; the two are often used together.

What is the most common obturation technique and material, and what is the sealer's role?

Gutta-percha (core material) with a root canal sealer, commonly via lateral or warm vertical compaction. The sealer fills voids/irregularities, seals the gutta-percha to canal walls, and entombs residual bacteria.

What is the management of a 'hot tooth' (irreversible pulpitis emergency), and why can anesthesia be difficult?

Emergency pulpectomy (or pulpotomy) to remove inflamed tissue and relieve pain. Anesthesia is difficult due to lowered pain threshold of inflamed tissue and altered sodium channels; supplemental intraligamentary/intraosseous/intrapulpal injections are often needed.

When is endodontic retreatment indicated versus apical surgery?

Nonsurgical retreatment is preferred when the previous root filling is inadequate and the canal can be re-accessed (persistent infection, missed canals). Apical surgery (apicoectomy) is indicated when orthograde retreatment is not feasible (e.g., post, blockage) or fails.

Differentiate direct pulp cap, indirect pulp cap, and pulpotomy.

Indirect pulp cap: medicament over a thin layer of remaining caries/dentin near pulp (no exposure). Direct pulp cap: medicament placed directly on a small pulp exposure. Pulpotomy: removal of coronal pulp tissue, preserving vital radicular pulp.

What materials are used for vital pulp therapy and why are bioceramics (MTA) favored?

Calcium hydroxide and bioceramics (MTA, Biodentine). MTA is favored for its excellent biocompatibility, sealing ability, high pH/antibacterial action, and reliable hard-tissue (dentin bridge) induction with less breakdown than calcium hydroxide.

What is the difference between apexification and apexogenesis?

Apexogenesis: vital pulp therapy in an immature tooth allowing continued root development and natural apical closure. Apexification: inducing an apical barrier (MTA plug or Ca(OH)2) in a non-vital immature tooth where root development has ceased.

What are the biologic principles of crown preparation regarding taper, finish line, and biologic width?

Total occlusal convergence (taper) ~6-10 degrees for retention; clear finish line (chamfer/shoulder) with adequate reduction (~1.5-2 mm occlusal); and margins must respect biologic width (~2 mm of attachment apical to sulcus base) to avoid gingival inflammation.

State Ante's Law for fixed partial dentures.

The total periodontal ligament surface area of the abutment teeth should be equal to or greater than that of the teeth being replaced by the pontic(s). It guides whether abutments can support the prosthesis.

What are the components of a removable partial denture (RPD)?

Major connector, minor connectors, rests (occlusal/cingulum/incisal), direct retainers (clasp assemblies), indirect retainers, and the denture base with artificial teeth.

What is the Kennedy classification of partially edentulous arches?

Class I: bilateral edentulous areas posterior to natural teeth (distal extension). Class II: unilateral distal extension. Class III: unilateral edentulous area with teeth anterior and posterior. Class IV: single edentulous area anterior to (crossing) the midline.

What is the purpose of an indirect retainer in a distal-extension RPD?

It prevents rotation/lifting of the distal extension base away from the tissue by resisting movement around the fulcrum line; placed anterior to the fulcrum line (e.g., a rest on a tooth) to counter the tissue-ward forces.

In complete denture fabrication, what is the difference between centric relation and balanced occlusion?

Centric relation is the maxillomandibular relationship with condyles in their most superior-anterior position in the glenoid fossa, independent of tooth contact - the reproducible reference for denture fabrication. Balanced occlusion is bilateral, simultaneous contact of teeth in centric and eccentric positions to stabilize the denture during function.

What is the difference between centric relation (CR) and centric/maximum intercuspation (CO/MIP)?

Centric relation (CR) is the bone-to-bone condylar reference position (condyles superior-anterior, independent of teeth). Centric occlusion / maximum intercuspation (MIP) is the position of maximum tooth interdigitation. They may coincide or differ (CR-CO slide).