HK Dental ORE cheat sheet

Part I is a single best-answer MCQ paper across the biomedical and clinical sciences; each item has one defensibly best option, so eliminate options containing absolutes ('always', 'never') unless the fact is genuinely absolute.

Restoration-tooth proportion rule: for a posterior tooth, remaining pericervical dentin and ferrule (≥1.5–2 mm circumferential) drive the decision between direct composite, onlay, and full coverage; a cusp-replacing restoration needs cuspal coverage when the isthmus width exceeds one-third of the intercuspal distance.

Pulp diagnosis uses four categories: normal, reversible pulpitis (sharp provoked pain, no spontaneous pain), symptomatic/asymptomatic irreversible pulpitis (spontaneous or lingering pain, or necrotic with apical periodontitis), and previously treated/previously initiated therapy.

Antibiotic prophylaxis for infective endocarditis (NICE/ADA-style reasoning): highest-risk groups only - prosthetic valve or material, previous IE, certain congenital heart disease, cardiac transplant with valvulopathy; standard regimen is a single dose 30–60 minutes pre-procedure.

Local anaesthetic maximum doses (mg/kg, with vasoconstrictor): lidocaine 4.4, articaine 7, mepivacaine 6.6, prilocaine 8, bupivacaine 1.6; calculate mg = % concentration × 10 × mL, then divide by weight to check the cap.

Periodontal diagnosis: staging uses interdental clinical attachment loss (stage I ≤2 mm, II 3–4 mm, III ≥5 mm, IV ≥5 mm plus tooth loss/masticatory dysfunction); grading uses bone loss/age ratio and HbA1c or smoking to assign progression risk A/B/C.

Dental material selection logic: amalgam for high-load posterior contacts where moisture control is difficult; resin composite where aesthetics and minimal preparation dominate; glass ionomer for high caries risk and root surfaces because of fluoride release and chemical adhesion.

Radiographic interpretation sequence for MCQs: caries (radiolucency limited to enamel vs reaching dentin), periapical status (widened PDL, loss of lamina dura), bone level, and incidental findings such as retained roots or idiopathic osteosclerosis.

Class II cavity preparation on a typodont: proximal box width should be just enough to clear contact (about 0.5 mm beyond), gingival seat flat and at or just above the gingival margin, and the cavosurface margin must be a butt joint with no unsupported enamel.

Rubber dam isolation is scored on correct clamp selection (bow size and jaw shape matched to molar/premolar/anterior), stable seal, and evidence of a dry field; leaking dams are a common failure point during adhesive procedures.

Endodontic access and canal location: straight-line access with the bur aligned to the long axis, then verify canal orifices (MB1/MB2 in maxillary molars, two mesial canals in mandibular molars) before instrumenting; the working length is confirmed radiographically 0.5–1 mm short of the apex.

Suturing technique: instrument tie with square knots, wound edges everted and apposed without tension, bites 2–3 mm from the margin and 2–3 mm apart; removal timing is typically 5–7 days for oral mucosa.

Impression technique: use a stock tray with appropriate spacer, border-moulded elastomer, and record the full sulcus and functional depth; voids, drags, and tray show-through are the standard faults examiners look for.

Local anaesthetic administration is assessed on landmark accuracy: inferior alveolar nerve block targets the pterygomandibular space with the needle at the contralateral premolars, 6–10 mm barrel depth, and aspiration before deposition.

Instrument handling and ergonomics: finger rest on stable teeth, indirect vision via mirror for palatal and lingual surfaces, and a consistent clock-face hand position are scored, not just the final preparation.

Infection control in the practical station: hand hygiene before gloving, correct PPE sequence, sharps disposal immediately after use, and no cross-contamination between the manikin and the instrument tray.

History structure: presenting complaint with SOCRATES-style characterisation, then medical history, medications (anticoagulants, bisphosphonates, immunosuppressants), allergies, smoking and alcohol, and social/occupational factors.

Extraoral examination sequence: inspection of face and profile, palpation of the temporomandibular joint and muscles of mastication, lymph node chains (submental, submandibular, cervical), and cranial nerve screening where indicated.

Intraoral soft tissue examination: systematic inspection of all mucosal sites, the lateral border of the tongue and floor of mouth (high-risk sites for squamous cell carcinoma), and any ulcer persisting beyond two weeks must be referred for urgent assessment.

Periodontal charting: record plaque and bleeding on probing at six sites per tooth, probing depths, recession, mobility, furcation involvement, and the presence of suppuration; a BPE score of 3 or 4 triggers full charting.

Occlusal and functional assessment: examine guidance in excursion, fremitus, parafunction signs (wear facets, abfraction, linea alba), and record the interincisal opening and any deviation on opening.

Special investigations are justified, not routine: periapical radiographs for suspected apical pathology, vitality testing (cold, EPT) to distinguish pulpal from periapical pain, and biopsy or referral for any lesion that does not resolve.

Treatment planning logic: stabilise the emergency, then disease control (caries, periodontal), then definitive restorative/prosthodontic work, then maintenance; the examiner looks for an explicit sequence and consent discussion.

Communication and professionalism are assessed: introduce yourself, gain consent before examination, explain findings in plain language, and document accurately in the record with a clear risk discussion.