Overseas Registration Exam (ORE) Prevention, Public Health and Medical Emergencies Syllabus

What are the Number Needed to Treat (NNT) and its formula?

NNT is the number of patients who must be treated to prevent one additional adverse outcome. $$\text{NNT}=\frac{1}{\text{ARR}}$$ where ARR (absolute risk reduction) $=$ control event rate $-$ experimental event rate. A smaller NNT means a more effective treatment.

What does a 95% confidence interval tell you, and how does it indicate statistical significance?

It is the range within which the true population value is expected to lie with 95% confidence. For a ratio (RR/OR) a result is statistically significant if the CI does NOT include 1; for a difference of means, if the CI does not include 0.

In the UK, what is 'Delivering Better Oral Health' (DBOH)?

An evidence-based toolkit for prevention produced by Public Health England / OHID for the whole dental team, giving consistent, graded preventive advice and interventions for patients across the life course (diet, fluoride, plaque control, smoking, alcohol).

According to DBOH, what fluoride toothpaste concentration is recommended for adults and for children?

Adults and children: brush twice daily with fluoride toothpaste. Adults/children ≥3 yrs use $\geq 1350\text{–}1500\ \text{ppm}$ F. Children under 3 use a smear of $\geq 1000\ \text{ppm}$ F; 3–6 yrs use a pea-sized amount. Higher-risk patients may be prescribed 2800 or 5000 ppm paste.

What does DBOH advise about rinsing after toothbrushing, and why?

Spit out after brushing but do NOT rinse with water ('spit, don't rinse'). Rinsing washes away the concentrated fluoride, reducing its remineralising effect; not rinsing maintains a higher intra-oral fluoride reservoir.

What is the recommended frequency and concentration for professionally applied fluoride varnish in caries prevention?

Fluoride varnish containing $22{,}600\ \text{ppm}$ F ($5\%$ sodium fluoride, NaF) applied at least twice yearly; for higher-risk children/patients it may be applied up to 3–4 times per year (and from age 2 upward).

What is the key public health message linking sugar to caries (frequency vs amount)?

It is the frequency of free-sugar intake (number of acid attacks), not just the total amount, that drives caries. Each sugar exposure produces a Stephan-curve pH drop; reducing the frequency of sugar intake limits the time enamel spends below the critical pH.

State the critical pH for enamel demineralisation.

Approximately $\text{pH}\ 5.5$ for enamel. Below this value hydroxyapatite dissolves (demineralisation); the critical pH for root dentine/cementum is higher, around $\text{pH}\ 6.0\text{–}6.7$.

What is the WHO/UK recommended maximum intake of free sugars?

Free sugars should provide less than 5% of total dietary energy intake (UK SACN recommendation), equivalent to roughly $30\ \text{g}$ ($\approx 7$ teaspoons) per day for an average adult.

What is a diet diary in caries prevention and how is it best used?

A 3–4 day food/drink record (including at least one non-working day) recording timing, content and frequency of intake. The clinician analyses it to identify hidden and frequent free-sugar exposures and acidic intakes, then gives tailored, achievable dietary advice.

List the '5 A's' model for tobacco brief intervention.

Ask (about tobacco use), Advise (to quit, personalised), Assess (willingness/readiness to quit), Assist (offer support, NRT, referral), Arrange (follow-up / referral to stop-smoking services). A briefer model is the 'Very Brief Advice': Ask, Advise, Act.

Name common pharmacotherapies offered to support smoking cessation.

Nicotine replacement therapy (patches, gum, lozenge, inhalator, spray), varenicline (a nicotinic partial agonist), and bupropion (an atypical antidepressant). NRT can combine a long-acting patch with a short-acting form.

What is the UK recommended low-risk limit for alcohol consumption, and what is alcohol brief advice?

No more than $14$ units per week for both men and women, spread over $\geq 3$ days with several drink-free days. Alcohol brief advice (e.g. using AUDIT-C screening followed by structured feedback and FRAMES) is a short, opportunistic intervention to motivate reduced drinking; alcohol and tobacco are the major risk factors for oral cancer.

What is the modified Bass toothbrushing technique?

The brush is angled at 45° to the gingival margin with bristles pointed apically into the gingival sulcus, using small vibratory/circular movements to disrupt plaque at and just below the gum line, then rolling/sweeping the bristles occlusally.

What interdental cleaning does DBOH recommend, and what governs the choice?

Clean interdentally daily. Interdental brushes are preferred where the space allows (more effective at plaque removal); dental floss/tape is used where spaces are too tight for a brush. Size of the interdental space and gingival recession govern the choice.

Name the stages of the Transtheoretical (Stages of Change) model used in behaviour change.

Precontemplation, Contemplation, Preparation, Action, Maintenance (and Relapse). Interventions are matched to the patient's stage to support movement toward sustained behaviour change.

What are 'SMART' goals in oral health behaviour change?

Specific, Measurable, Achievable, Relevant and Time-bound. Setting SMART goals with the patient improves the likelihood that agreed changes (e.g. reducing sugary snacks) are actually adopted and sustained.

Define decontamination and list its three component processes in order.

Decontamination is the combination of processes that renders a reusable item safe for further use/handling. The processes are: 1. Cleaning (removal of visible soil/bioburden), 2. Disinfection (reduction of viable microorganisms), 3. Sterilisation (destruction of all microorganisms including spores). Cleaning must always precede sterilisation.

State the standard steam (autoclave) sterilisation parameters for dental instruments.

Saturated steam under pressure: typically $134\text{–}137\,^{\circ}\text{C}$ at $\approx 2.1\ \text{bar}$ for a minimum holding time of $3$ minutes; an alternative cycle is $121\,^{\circ}\text{C}$ at $\approx 1.1\ \text{bar}$ for $15$ minutes.

Differentiate type N and type B (vacuum) autoclaves.

Type N (non-vacuum/downward displacement) sterilises only solid, unwrapped, non-lumened instruments. Type B (vacuum/porous-load) uses active air removal and can sterilise wrapped, hollow and lumened/cannulated instruments, allowing storage of pouched sterile items.

In Spaulding's classification, what are critical, semi-critical and non-critical items?

Critical = items entering sterile tissue or the vascular system (e.g. surgical instruments, scalers) — require sterilisation. Semi-critical = contact mucous membranes or non-intact skin (e.g. mirrors, handpieces) — require sterilisation or high-level disinfection. Non-critical = contact intact skin only (e.g. BP cuff) — require cleaning/low-level disinfection.

List the components of standard (universal) precautions in dentistry.

Hand hygiene; appropriate PPE; safe handling and disposal of sharps; environmental cleaning and decontamination of surfaces/equipment; respiratory hygiene/cough etiquette; safe management of clinical waste, linen and blood/body-fluid spillages. They are applied to ALL patients regardless of known infection status.

What are the WHO 'Five Moments for Hand Hygiene'?

1. Before touching a patient, 2. Before a clean/aseptic procedure, 3. After body-fluid exposure risk, 4. After touching a patient, 5. After touching the patient's surroundings.

What is the correct sequence for donning and doffing PPE?

Donning: gown/apron → mask/respirator → eye protection → gloves. Doffing (most contaminated first): gloves → eye protection → gown/apron → mask/respirator, performing hand hygiene after removal (and between steps as needed).

How is clinical (hazardous infectious) waste segregated by colour in UK dental practice?

Orange bags = infectious clinical waste (treated/incinerated). Yellow = infectious waste requiring incineration (e.g. medicinal/anatomical contaminated). Yellow sharps bin (orange lid) = non-medicinally contaminated sharps; yellow lid = sharps contaminated with medicines; purple lid = cytotoxic/cytostatic. Black/clear = domestic (offensive yellow-black 'tiger' = non-infectious offensive).

State the key sharps-safety rules to prevent inoculation injury.

Do not re-sheathe needles by hand (use single-handed scoop or a re-sheathing device); never bend/break needles; dispose of sharps at the point of use into a designated puncture-resistant sharps bin; fill bins to the marked line only; the person who used the sharp is responsible for its disposal.

List the main blood-borne viruses of occupational concern and their relative transmission risk after a needlestick from a positive source.

Hepatitis B (HBV) — highest risk, up to ~30% if e-antigen positive and recipient unvaccinated; Hepatitis C (HCV) — approximately 3%; HIV — approximately 0.3% after percutaneous exposure.

Outline the immediate first-aid and management steps after a sharps/needlestick injury.

Encourage the wound to bleed (do not suck), wash with running water and soap (do not scrub); irrigate exposed mucosa/eyes with water/saline; report to the responsible person and occupational health; perform a risk assessment of the source; consider PEP (especially for HIV within ideally 1 hour), check/boost HBV status, and arrange baseline and follow-up serology.

What HBV protection should dental clinical staff have, and what indicates immunity?

They should be vaccinated against hepatitis B (and ideally be 'EPP-cleared'). An anti-HBs (surface antibody) titre $\geq 100\ \text{mIU/mL}$ indicates an adequate response; $10\text{–}100$ is a poor responder needing a booster; $< 10\ \text{mIU/mL}$ is a non-responder requiring investigation and possibly HBIG after exposure.

What does the ABCDE approach to the acutely unwell patient stand for?

A = Airway, B = Breathing, C = Circulation, D = Disability (neurological status, e.g. AVPU/GCS and blood glucose), E = Exposure (examine for other clues while preventing heat loss). Assess and treat life-threatening problems in order before moving on.

How do you recognise and manage a vasovagal syncope (simple faint) in the dental chair?

Recognition: pre-syncope pallor, sweating, nausea, slow weak pulse, then loss of consciousness. Management: lay the patient flat and raise the legs to restore cerebral perfusion, ensure a clear airway, give oxygen, loosen tight clothing; recovery is usually rapid — consider glucose if delayed.

Describe the recognition and emergency management of acute anaphylaxis.

Recognition: rapid onset of Airway/Breathing/Circulation problems (stridor, wheeze, hypotension) with skin changes (urticaria, angioedema) after an allergen. Management: ABCDE, remove trigger, give IM adrenaline $0.5\ \text{mg}$ ($0.5\ \text{mL}$ of $1{:}1000$) into the anterolateral thigh, high-flow oxygen, lie flat with legs raised, call 999/2222, repeat adrenaline after 5 minutes if no improvement.

What is the adult basic life support sequence and the CPR ratio?

Ensure safety, check response, open airway, check for normal breathing (no more than 10 s); if absent, call for help/999 and AED, start chest compressions. Give 30 compressions to 2 rescuer breaths ($30{:}2$), compressions at a depth of $5\text{–}6\ \text{cm}$ and a rate of $100\text{–}120$ per minute.

In adult cardiac arrest, which rhythms are shockable, and where does adrenaline fit?

Shockable rhythms: ventricular fibrillation (VF) and pulseless ventricular tachycardia (pVT) — defibrillate immediately. Non-shockable: pulseless electrical activity (PEA) and asystole. Adrenaline $1\ \text{mg}$ IV/IO is given immediately in non-shockable rhythms, and after the 3rd shock in shockable rhythms, then repeated every $3\text{–}5$ minutes.

List the emergency drugs that must be available in a UK dental practice (Resuscitation Council/DBOH).

Oxygen; adrenaline $1{:}1000$ (1 mg/mL) IM; aspirin $300\ \text{mg}$ (dispersible); glyceryl trinitrate (GTN) spray; salbutamol inhaler; glucagon $1\ \text{mg}$ IM; oral glucose (e.g. GlucoGel) / glucose tablets; midazolam (buccal/oromucosal $10\ \text{mg}$ or IM) for prolonged seizures.

What essential emergency equipment must a dental practice keep for resuscitation?

Portable oxygen cylinder with pressure-reduction valve and flowmeter; oxygen masks (non-rebreathe) and tubing; self-inflating bag-valve-mask with reservoir (adult/child); oropharyngeal (Guedel) airways of assorted sizes; pocket mask with oxygen port; portable suction with wide-bore aspirator (Yankauer); spacer device for inhalers; and an automated external defibrillator (AED) with pads.

How is a hypoglycaemic emergency managed in a conscious versus an unconscious dental patient?

Conscious and able to swallow: give fast-acting oral glucose (e.g. glucose drink/gel, $15\text{–}20\ \text{g}$), repeat in 10–15 min if needed, then a longer-acting carbohydrate. Unconscious/unable to swallow: protect airway, give oxygen, administer glucagon $1\ \text{mg}$ IM and call 999; if IV access available, give IV glucose.

What is the emergency drug management of an acute asthma attack in the dental surgery?

Sit the patient upright, give high-flow oxygen, and administer salbutamol via inhaler with a spacer — 2 puffs, repeated up to $4\text{–}6$ (or up to 10) puffs every 10 minutes. If no response, life-threatening features, or worsening, call 999 and continue salbutamol pending paramedics.

Describe immediate management of suspected acute myocardial infarction / angina in the chair.

Stop treatment, sit the patient up, reassure. For angina give sublingual GTN spray and oxygen if hypoxic; if pain persists after GTN or MI is suspected, call 999, give a single dose of aspirin $300\ \text{mg}$ chewed (if not contraindicated), monitor ABCDE and be prepared for cardiac arrest/BLS.