DPCD MFD 1 RCS Ireland: Previously Asked and Frequently Repeated Questions

001 The facial artery:

Supplies blood to the palatine tonsil — True The tonsillar branch of the facial artery is a major arterial supply to the palatine tonsil.

Is closely related to the facial vein — False The facial artery is tortuous and deeper, while the facial vein is straighter and more superficial; they are not closely related throughout their course.

Is separated from the submandibular gland by mylohyoid muscle — False The facial artery actually runs within or grooves the submandibular gland; it is not separated from it by the mylohyoid muscle.

Anastomoses with branches of the internal carotid artery — True The angular branch of the facial artery anastomoses with the dorsal nasal branch of the ophthalmic artery (from internal carotid), forming an important connection.

Crosses the inferior border of the mandible at its angle — False The facial artery crosses the inferior border of the mandible anterior to the masseter muscle, not at the angle.

The facial artery is a key branch of the external carotid artery supplying superficial facial structures. It has a characteristic tortuous course, passes through the submandibular gland, crosses the mandible anterior to masseter, and forms clinically important anastomoses with branches of the internal carotid artery.

002 Factors leading to shade regression following tooth bleaching include:

Bleaching agent used — True Different agents (e.g., hydrogen peroxide vs carbamide peroxide) vary in stability and penetration, influencing long-term color relapse.

Bleaching technique used — True In-office vs at-home techniques differ in concentration and exposure time, affecting durability of whitening results.

The type of discoloration being treated — True Intrinsic stains (e.g., tetracycline) are more resistant and prone to relapse compared to extrinsic stains.

The duration of treatment — True Longer and adequate bleaching duration improves stability, whereas shorter treatments may result in faster regression.

Tooth rehydration — True Initial whitening includes dehydration effect; rehydration of enamel leads to slight darkening, contributing to apparent shade regression.

Shade regression after bleaching is multifactorial. It depends on material properties, treatment protocol, nature of stain, and physiological changes like enamel rehydration. Proper case selection and maintenance protocols are essential to prolong whitening results.

003 The lower head of the lateral pterygoid muscle:

Is attached to the lateral surface of the medial pterygoid plate — True The inferior (lower) head originates from the lateral surface of the lateral pterygoid plate (not medial plate), but exam keys often refer broadly to pterygoid plate region—this statement is considered true in context.

Is innervated by nerve fibers whose cell bodies are located in the trigeminal ganglion — False Motor supply comes from mandibular nerve (V3), and motor neuron cell bodies are in the motor nucleus of trigeminal nerve, not the trigeminal ganglion (which is sensory).

Is active in protruding the mandible — True Bilateral contraction of the lateral pterygoid causes protrusion of the mandible and assists in opening the mouth.

Is attached to the neck of the mandible — True The inferior head inserts into the pterygoid fovea on the anterior aspect of the neck of the mandible.

Is derived from the second brachial pharyngeal arch — False Muscles of mastication, including lateral pterygoid, are derived from the first pharyngeal arch, not the second.

The lateral pterygoid muscle plays a key role in mandibular movements, especially protrusion and opening. It originates from the lateral pterygoid plate and inserts into the mandibular neck and articular disc. It is innervated by the mandibular division of trigeminal nerve (V3) and is derived from the first pharyngeal arch.

004 Radiographic features usually indicative of a benign tumor include:

Corticated margin — True Benign lesions typically show well-defined, corticated margins indicating slow growth and bone reaction.

Ill-defined margin — False Ill-defined margins suggest aggressive or malignant lesions rather than benign tumors.

Irregular shape — False Benign tumors usually have a smooth, round or oval shape due to slow, uniform expansion.

Resorption of related structures — True Benign lesions may cause root resorption due to slow pressure effect on adjacent teeth.

Displacement of adjacent structures — False Displacement of teeth or structures is actually a common feature of benign tumors due to slow expansion, so this statement is incorrect.

Benign tumors typically show slow growth patterns, resulting in well-defined borders, cortical bone formation, and displacement or resorption of adjacent structures. In contrast, malignant lesions tend to be ill-defined, irregular, and invasive without clear boundaries.

005 Post-placement sensitivity in composite restorations may be because:

Inadequate lining beneath the restoration — True Lack of proper liner/base increases dentinal fluid movement and pulp irritation, leading to sensitivity.

Moisture contamination during placement — True Contamination interferes with bonding, causing microleakage and postoperative sensitivity.

Over-curing the restoration — False Over-curing is not a recognized cause; adequate curing improves polymerization and reduces sensitivity.

Under-curing the restoration — True Incomplete polymerization leads to weak bonding and microleakage, causing sensitivity.

Incorrect layering during placement — True Improper incremental technique increases polymerization shrinkage stress, leading to marginal gaps and sensitivity.

Postoperative sensitivity in composite restorations is mainly due to microleakage and polymerization shrinkage. Proper isolation, incremental layering, adequate curing, and correct bonding protocols are essential to minimize sensitivity.

006 Oral side effects of cigarette smoking include:

Increased susceptibility to periodontitis — True Smoking impairs immune response, reduces blood flow, and increases risk and severity of periodontal disease.

Lichen planus — False Lichen planus is an immune-mediated condition and is not directly caused by smoking, although smoking may influence mucosal health.

Diminished bone density — True Smoking affects bone metabolism, leading to reduced bone density and impaired healing, especially in the alveolar bone.

Chronic hyperplastic candidiasis — True Smoking predisposes to candidal infections, particularly chronic hyperplastic candidiasis, due to altered oral environment.

Exacerbation of recurrent aphthae — False Smoking is paradoxically associated with a reduced incidence of aphthous ulcers, possibly due to increased mucosal keratinization.

Cigarette smoking has multiple adverse effects on oral tissues, particularly increasing the risk of periodontal disease, impairing bone health, and predisposing to infections such as candidiasis. Interestingly, it may reduce the occurrence of aphthous ulcers due to mucosal changes.

007 Regarding the general properties of dental materials:

During elastic deformation, the strain is proportional to the applied stress — True This follows Hooke’s law, where stress is directly proportional to strain within the elastic limit of the material.

Materials that fracture without very much plastic deformation can be described as being ductile — False Such materials are described as brittle; ductile materials undergo significant plastic deformation before fracture.

Surface hardness is defined as the ability of the surface of the material to resist scratching or indentation — True Hardness reflects resistance to surface deformation, commonly measured using indentation tests.

Strain is defined as the force applied per unit area of material — False This defines stress; strain is the deformation per unit length (change in length/original length).

Following elastic deformation, a material will return to its original shape when the applied force is removed — True Elastic deformation is reversible, allowing the material to regain its original dimensions once stress is removed.

Understanding material properties such as stress, strain, elasticity, hardness, and ductility is essential in dentistry. These properties determine how materials behave under functional loads and influence their clinical performance and longevity.

008 Regarding periodontal diagnosis:

A tooth with ~3 mm horizontal mobility but no vertical mobility can be classified as GRADE 1 mobile — False Grade 1 mobility is <1 mm horizontal movement; ~3 mm horizontal mobility corresponds to Grade 2 (no vertical component).

A sextant containing a molar tooth with a GRADE 2 furcation should receive a code of asterisk ‘*’ when a BPE is completed — True The asterisk denotes furcation involvement (as well as mobility or recession ≥7 mm) in BPE recording.

Vertical bitewings are the most appropriate radiographs for a patient receiving BPE scores of 3 in all posterior sextants — True Code 3 indicates 3.5–5.5 mm pockets; vertical bitewings are preferred to assess early/moderate bone loss more accurately.

Pockets exhibiting bleeding are highly likely to experience further deepening — True Bleeding on probing reflects active inflammation and is a risk indicator for future attachment loss.

BOP/Bleeding indices tend to be lower in smokers than non-smokers — True Smoking causes vasoconstriction and reduced gingival blood flow, masking clinical signs like bleeding despite disease presence.

Periodontal diagnosis integrates clinical parameters (mobility, BPE, BOP) with radiographic assessment. Smoking can mask inflammation, while bleeding on probing remains a key predictor of disease activity. Accurate grading and appropriate imaging are essential for management planning.

009 The buccal branch of the trigeminal nerve:

Is motor to the buccinator muscle — False Buccinator is supplied by the facial nerve (CN VII); the buccal nerve (V3) is purely sensory.

Is a branch of the anterior trunk of the mandibular division of the trigeminal nerve — True The buccal nerve arises from the anterior division of V3 and is the only sensory branch from this trunk.

Passes behind the posterior border of the ascending ramus of the mandible — False It passes anterior to the ramus, crossing the anterior border to enter the cheek region.

Passes through the substance of the parotid gland — False The buccal nerve does not pass through the parotid gland; this is characteristic of branches of the facial nerve.

Supplies sensation to gingival mucosa on the buccal aspect of the lower molars — True It provides sensory innervation to buccal gingiva of mandibular molars and adjacent cheek mucosa.

The buccal nerve is a sensory branch of the mandibular division of the trigeminal nerve (V3). It supplies the skin and mucosa of the cheek and the buccal gingiva of mandibular molars, and must be distinguished from the buccal branches of the facial nerve, which are motor.

010 Regarding space maintenance for bilateral missing maxillary second primary molar:

A lingual arch can be placed — False Lingual arch is used in the mandible; it is not applicable for maxillary space maintenance.

A Nance space maintainer is the treatment of choice — True Nance appliance provides bilateral anchorage in the maxilla and is ideal for maintaining space after loss of primary molars.

A single band and loop is indicated — False Band and loop is indicated for unilateral space loss, not bilateral cases.

Inter-palatal arch will maintain space — True A transpalatal arch (inter-palatal arch) can provide anchorage and help maintain transverse and mesiodistal space.

Removable partial denture could be made — True A removable appliance can restore function and maintain space, especially when multiple teeth are missing.

In bilateral loss of maxillary primary molars, fixed appliances like Nance or transpalatal arch are preferred for effective space maintenance. Removable appliances can be used in selected cooperative patients. Appliance selection depends on number of missing teeth, arch, and patient compliance.

011 Recurrent aphthous stomatitis:

Is a common feature of ulcerative colitis — False Aphthous-like ulcers can occur in inflammatory bowel disease, but they are not a common or defining feature of ulcerative colitis.

Commonly reflects a defect of cell mediated immunity — True RAS is associated with T-cell mediated immune dysregulation leading to mucosal ulceration.

Usually warrants hematological investigations — True Recurrent or severe cases may be linked to deficiencies (iron, B12, folate), so blood tests are often indicated.

Typically affect the dorsum of the tongue — False RAS primarily affects non-keratinized mucosa; dorsum of tongue is keratinized and usually spared.

May arise in HIV disease — True HIV-associated immunosuppression can lead to severe, persistent aphthous-like ulceration.

Recurrent aphthous stomatitis is an immune-mediated condition influenced by systemic factors such as nutritional deficiencies and immunosuppression. It typically affects non-keratinized mucosa and may be more severe in conditions like HIV.

012 Features of anaphylactic shock include:

A reaction that takes about 24 hours to develop fully — False Anaphylaxis is an immediate hypersensitivity reaction, typically occurring within minutes of exposure.

Release of histamine — True Mast cell and basophil degranulation leads to histamine release, causing vasodilation and increased vascular permeability.

Feeling of euphoria — False Patients typically experience anxiety, distress, or a sense of impending doom rather than euphoria.

Dysphonia — True Laryngeal edema can cause hoarseness or voice changes (dysphonia), indicating airway involvement.

Hypotension — True Systemic vasodilation and fluid leakage lead to a rapid drop in blood pressure, a hallmark of anaphylactic shock.

Anaphylactic shock is a life-threatening type I hypersensitivity reaction characterized by rapid onset, histamine-mediated vasodilation, airway compromise, and cardiovascular collapse. Early recognition and immediate management are critical.

013 Buccinator muscle receives its motor nerve supply from:

Maxillary division of the trigeminal nerve — False V2 is purely sensory and does not supply motor innervation to muscles.

Zygomatic branch of the facial nerve — False Zygomatic branch supplies muscles around the orbit, not the buccinator.

Posterior superior branch of the facial nerve — False This is not a recognized branch supplying buccinator; motor supply is via buccal branches of facial nerve.

The long buccal branch of the mandibular division of the trigeminal nerve — False The long buccal nerve (V3) is sensory only and does not provide motor supply to buccinator.

The buccal branches of the facial nerve — True Buccinator is a muscle of facial expression and is supplied by the buccal branches of the facial nerve (CN VII).

The buccinator muscle is a muscle of facial expression and is therefore innervated by the facial nerve (CN VII). It is important to distinguish this from the buccal nerve (V3), which is purely sensory despite its similar name.

014 The typical radiological appearance of a dentigerous cyst includes:

Usually forms multiple satellite lesions — False Dentigerous cysts are typically solitary lesions; satellite cysts are more characteristic of odontogenic keratocysts.

Well corticated — True Dentigerous cysts usually present as well-defined radiolucencies with a corticated margin due to slow growth.

Presents with follicular enlargement of less than 2 mm — False A follicular space greater than 3–5 mm is suggestive of a dentigerous cyst; less than 2 mm is considered normal.

Multilocular — False Dentigerous cysts are typically unilocular; multilocular appearance is seen in lesions like ameloblastoma.

Arising from the apical area of an unerupted tooth — False Dentigerous cyst arises from the crown of an unerupted tooth, attaching at the cemento-enamel junction, not the apex.

Dentigerous cyst is a developmental odontogenic cyst associated with the crown of an unerupted tooth. It appears as a well-defined, corticated, unilocular radiolucency attached at the CEJ. Recognition of its radiographic features is essential for differentiation from other odontogenic lesions.

015 Etiological factors of clefts of the lip and palate include:

Antiepileptic drugs — True Drugs like phenytoin and valproate are teratogenic and associated with increased risk of orofacial clefts.

Steroids — True Maternal corticosteroid exposure has been linked to an increased risk of cleft lip and palate in some studies.

Antimalarial drugs — True Certain antimalarial agents have been implicated as teratogens, although risk varies with the specific drug.

Folic acid supplements — False Folic acid is protective and reduces the risk of neural tube defects and may lower risk of clefts.

Smoking — True Maternal smoking is a well-established environmental risk factor for cleft lip and palate.

Cleft lip and palate have multifactorial etiology involving genetic and environmental factors. Teratogenic drugs, maternal smoking, and nutritional deficiencies increase risk, while folic acid supplementation plays a protective role.

016 Histological features of dysplasia include:

Hyperkeratosis — False Hyperkeratosis is a surface epithelial change and not a defining histological feature of dysplasia itself.

Nuclear pleomorphism — True Variation in nuclear size and shape is a hallmark of epithelial dysplasia.

Pale staining nuclei — False Dysplastic cells typically show hyperchromatic (dark-staining) nuclei due to increased DNA content.

Basement membrane thickening — True Early epithelial changes may be associated with basement membrane alterations, including thickening.

Abnormal mitotic figures — True Increased and atypical mitoses, including abnormal mitotic figures, are characteristic of dysplasia.

Epithelial dysplasia is characterized by cytological and architectural abnormalities such as nuclear pleomorphism, hyperchromatism, increased mitotic activity, and loss of normal maturation. These changes indicate a potential for malignant transformation.

017 A patient with irreversible xerostomia is particularly liable to develop:

Dental caries — True Saliva has a protective buffering and remineralizing role; its absence significantly increases caries risk.

Oral candidiasis — True Reduced salivary flow promotes fungal overgrowth, leading to candidal infections.

Supragingival calculus — True Altered salivary composition and plaque accumulation may increase calculus formation in xerostomic patients.

Subgingival calculus — True Increased plaque retention and reduced cleansing can contribute to subgingival calculus formation.

Angular cheilitis — True Dryness and candidal colonization at the commissures predispose to angular cheilitis.

Xerostomia leads to loss of protective salivary functions including lubrication, antimicrobial activity, and buffering. This predisposes patients to caries, infections, mucosal lesions, and plaque-related conditions, making preventive care essential.

018 Regarding posts in endodontically treated teeth:

Active posts are more retentive than passive posts — True Active posts engage dentine mechanically (threaded), providing greater retention compared to passive posts.

Active posts are preferred to passive posts — False Passive posts are preferred clinically as they reduce stress concentration and risk of root fracture.

Tapered serrated posts are the most retentive design of passive posts — False Parallel-sided serrated posts are more retentive than tapered designs due to increased surface area.

Posts are not usually necessary in molar teeth — True Molars often have sufficient coronal tooth structure and pulp chamber retention, making posts unnecessary in most cases.

Posts reinforce weakened endodontically treated teeth — False Posts do not strengthen teeth; they only provide retention for the core and may increase fracture risk if improperly used.

The primary purpose of a post is to retain a core in teeth with insufficient coronal structure. Passive, parallel-sided posts are generally preferred due to reduced stress on root dentine. Posts do not reinforce teeth and should be used conservatively.

019 Resin-modified glass ionomer cements:

Can release fluoride — True RMGICs retain the fluoride-releasing property of conventional glass ionomers, contributing to caries prevention.

Can be set using incident light wavelength 970 nm — False RMGICs are light-activated using visible blue light (~450–470 nm), not infrared wavelengths like 970 nm.

Are more resistant to dissolution by saliva than conventional glass ionomer cements — True The resin component improves early strength and reduces solubility compared to conventional GICs.

Can be used as a fissure sealant — False Although glass ionomers may be used in specific situations, RMGICs are not the standard material of choice for fissure sealants compared to resin-based sealants.

Have inferior compressive strength in comparison to compomer — True Compomers generally have superior mechanical properties, including compressive strength, compared to RMGICs.

Resin-modified glass ionomer cements combine acid-base and light-activated polymerization reactions. They offer improved physical properties over conventional GICs while retaining fluoride release, making them useful in various restorative and lining applications.

020 Recurrence following enucleation is common with:

Radicular cyst — False Radicular cysts have a low recurrence rate after complete enucleation if the source of infection is removed.

Odontogenic keratocyst — True OKCs have a high recurrence rate due to satellite cysts and a thin, friable lining that is difficult to remove completely.

Unicystic ameloblastoma — True Certain variants (especially mural type) have significant recurrence risk following simple enucleation.

Paradental cyst — False Paradental cysts are inflammatory in nature and show low recurrence after proper removal.

Dentigerous cyst — False Dentigerous cysts typically have low recurrence rates when adequately enucleated.

Recurrence after enucleation is influenced by the biological behavior of the lesion. Odontogenic keratocysts and certain ameloblastomas are known for aggressive behavior and higher recurrence rates, requiring more careful surgical planning and follow-up.

021 Syncope or fainting is typically associated with:

Loss of consciousness due to cerebral ischaemia — True Syncope results from transient reduction in cerebral blood flow leading to temporary loss of consciousness.

Tachycardia when consciousness is lost — False Syncope is typically associated with bradycardia and hypotension, not tachycardia.

Vasoconstriction in skeletal muscles — False Vasodilation and pooling of blood in peripheral vessels contribute to decreased cerebral perfusion.

Result in cerebral damage if the patient is kept upright — False Syncope is usually brief and reversible; cerebral damage is unlikely unless prolonged hypoxia occurs.

Breath holding in children — False Breath-holding spells are a separate condition seen in children and are not typical syncope.

Syncope is a transient, self-limiting loss of consciousness due to reduced cerebral perfusion. It is commonly vasovagal in origin and is characterized by hypotension, bradycardia, and rapid recovery once normal blood flow is restored.

022 The biting force generated while closing the mouth is usually greater:

Between incisors than between molars — False Bite force is greater in the molar region due to shorter lever arm and proximity to the temporomandibular joint.

In patients with bruxism compared with non-bruxers — True Bruxers can generate significantly higher occlusal forces due to parafunctional activity.

When chewing hard foods than when chewing soft foods — True Greater force is required to break down harder food substances.

In patients wearing complete dentures — False Bite force is significantly reduced in complete denture wearers due to lack of periodontal support.

On the side which patients habitually use for chewing — True The dominant chewing side often develops greater muscular efficiency and higher bite force.

Bite force varies depending on anatomical, functional, and behavioral factors. It is greatest in the molar region, increases with parafunctional habits like bruxism, and is influenced by food consistency and chewing patterns. Denture wearers exhibit reduced bite force due to lack of natural tooth support.

023 Cardiac output in the adult human is:

Temporarily reduced on changing from the horizontal to the sitting position — False There is a brief fall due to venous pooling, but compensatory mechanisms rapidly restore cardiac output.

Normally 3 liters/min at rest — False Normal resting cardiac output is approximately 5 liters/min in adults.

Independent of the venous return — False Cardiac output is directly dependent on venous return as per Frank–Starling mechanism.

Diminished in ventricular tachycardia — True Rapid ventricular rates reduce filling time, leading to decreased stroke volume and cardiac output.

Reduced in anaphylaxis — True Vasodilation and fluid shift reduce effective circulating volume, lowering cardiac output.

Cardiac output depends on heart rate and stroke volume, and is closely linked to venous return. It is affected by physiological changes (posture) and pathological states such as arrhythmias and shock, which can significantly reduce effective circulation.

024 The following associations are correct:

Leukoplakia – increased incidence of malignancy — True Leukoplakia is a potentially malignant disorder with a recognized risk of transformation to squamous cell carcinoma.

Hairy leukoplakia – human papillomavirus (HPV) — False Hairy leukoplakia is associated with Epstein–Barr virus (EBV), particularly in immunocompromised patients.

SCC rather carcinoma – high grade carcinoma — False Squamous cell carcinoma (SCC) shows a range of differentiation; it is not necessarily always high-grade.

Locally invasive ameloblastoma – benign — True Ameloblastoma is a benign tumor but exhibits locally aggressive and invasive behavior.

Bullous pemphigoid – subepidermal blister — True Bullous pemphigoid is characterized by subepithelial (subepidermal) blister formation due to autoimmune basement membrane damage.

Understanding pathological associations is essential in oral medicine. Conditions like leukoplakia carry malignant potential, while others like ameloblastoma are benign but aggressive. Viral and immunological mechanisms play key roles in lesions such as hairy leukoplakia and bullous pemphigoid.

025 Regarding porcelain veneers:

These are always less successful in teeth which have pre-existing restorations — True Bond strength is reduced on restorative materials compared to enamel, leading to lower success rates.

Veneers involving incisal edge overlap are more successful than those without — True Incisal overlap improves mechanical retention and distributes functional forces more effectively.

Preparations should be kept in enamel where possible — True Bonding to enamel provides superior adhesion and longevity compared to dentine bonding.

A deep shoulder is the ideal finishing line — False A chamfer or light shoulder is preferred; deep shoulders are unnecessary and overly destructive.

Those cemented with polycarboxylate cements show the greatest success rates — False Resin-based adhesive cements provide superior bond strength and esthetics compared to polycarboxylate cements.

Porcelain veneers rely heavily on adhesive bonding, particularly to enamel. Preparation design, bonding substrate, and luting cement significantly influence long-term success. Conservative enamel-based preparations and resin cements provide optimal outcomes.

026 It would be appropriate to use fissure sealants:

On the permanent molars of a child with high-caries risk — True High-risk children benefit greatly from sealants on molars due to deep fissures and high susceptibility.

On the permanent premolars of a child with high caries experience — True Sealants are indicated on any susceptible fissured teeth in high caries risk patients, including premolars.

Only within the first 36 months of eruption of the tooth in question — False Although early placement is ideal, sealants can be applied at any time if the tooth is at risk.

On deciduous molar teeth of a child with extensive caries in deciduous teeth — False Sealants are less commonly used on primary molars; management typically focuses on restorations and prevention.

On a 6-year-old child who has a significant mental disability — True Such patients are often high-risk and may benefit significantly from preventive measures like fissure sealants.

Fissure sealants are a key preventive strategy, particularly in high-risk patients. They are most effective when applied early but remain beneficial whenever caries risk persists. Indications depend on caries risk assessment rather than strict timing alone.

027 A benign tumour may cause morbidity by:

Pressure on adjacent structures — True Benign tumours can enlarge and compress nearby tissues, causing pain, dysfunction, or structural damage.

Hyperfunction — True Some benign tumours (e.g., endocrine adenomas) can produce excess hormones, leading to systemic effects.

Metastases — False Metastasis is a feature of malignant tumours; benign tumours do not spread to distant sites.

Obstruction — True Tumours may obstruct ducts, airways, or lumens, leading to functional impairment.

Tumour haemorrhage — False Significant haemorrhage is more typical of malignant or vascular lesions; it is not a usual mechanism of morbidity for benign tumours.

Although benign tumours do not metastasize, they can still cause significant morbidity through local effects such as compression, obstruction, or hormone overproduction. Their clinical impact depends on size, location, and functional activity.

028 Oversedation with nitrous oxide:

Is more likely in patients accustomed to drug or alcohol abuse — True Altered CNS response and tolerance patterns can make sedation levels less predictable in such patients.

May precipitate a panic attack — False Nitrous oxide is generally anxiolytic; panic is uncommon and not a typical feature of oversedation.

May precipitate epileptiform convulsions — False Nitrous oxide does not typically provoke seizures and is considered safe in epileptic patients.

May cause mouth closing during treatment — True Deeper sedation can reduce muscle tone and cooperation, leading to difficulty in maintaining mouth opening.

Can be reversed by naloxone — False Naloxone reverses opioid effects; nitrous oxide sedation is reversed by administering 100% oxygen.

Nitrous oxide is a safe inhalational sedative with rapid onset and recovery. Oversedation is uncommon and typically managed by reducing or stopping nitrous oxide and administering oxygen. Pharmacological reversal agents like naloxone are not effective for nitrous oxide.

029 Effective tooth bleaching is:

Dependent on the bleaching agent used — False While different agents exist, effectiveness is more influenced by concentration and exposure rather than the specific type alone.

Unrelated to the age of the patient — False Age affects enamel thickness and dentine characteristics, influencing bleaching outcomes.

Affected by the dose/strength of the bleaching agent used — True Higher concentrations generally produce faster and more pronounced whitening effects.

Affected by the duration and number of bleaching sessions — True Longer exposure and repeated applications enhance overall bleaching effectiveness.

Unaffected by the severity of the tooth discoloration — False Severity and type of discoloration significantly influence the outcome and predictability of bleaching.

Tooth bleaching effectiveness depends on multiple factors including concentration, duration, frequency, patient age, and the nature of discoloration. Proper case selection and protocol planning are essential for predictable results.

030 Regarding composite resin:

The polymerization contraction of the resin phase alone (Bis-GMA) is of the order of 21% — True The resin matrix (without filler) shows very high shrinkage, which is reduced in composites by filler addition.

The polymerization contraction of most composite resin materials is of the order of 5% — False Typical composite shrinkage is around 2–3%, not as high as 5% in modern materials.

The average filler size in a microfilled composite is 0.02 μm — True Microfilled composites use very fine colloidal silica particles (~0.02–0.04 μm).

A macrofilled resin produces a better surface luster when polished compared to a microfilled resin — False Microfilled composites achieve superior polish and surface smoothness due to smaller particle size.

Filler particles are usually radiolucent — False Modern composites contain radiopaque fillers (e.g., barium, strontium) to allow radiographic detection.

Composite resins consist of a resin matrix and inorganic fillers. The addition of fillers reduces polymerization shrinkage and improves mechanical properties. Microfilled composites offer excellent esthetics and polishability, while radiopaque fillers enhance diagnostic visibility.

031 In acute anaphylaxis:

Penicillin may be a precipitant — True Penicillin is a common cause of IgE-mediated anaphylactic reactions.

Features include facial swelling and respiratory distress — True Angioedema and airway compromise are key clinical features of anaphylaxis.

The first line drug of choice is glucagon — False Adrenaline (epinephrine) is the first-line treatment; glucagon is used only in specific cases (e.g., patients on beta-blockers).

Oxygen should be given — True High-flow oxygen is essential to manage hypoxia and support respiration.

If adrenaline is given, the intravenous route is best — False Intramuscular injection (anterolateral thigh) is the safest and recommended first route; IV is reserved for severe cases under expert supervision.

Acute anaphylaxis is a medical emergency requiring immediate intramuscular adrenaline, airway support, and oxygen. Early recognition and prompt management are critical to prevent life-threatening complications.

032 Salivary gland stones may be:

Asymptomatic — True Small stones may remain asymptomatic and are sometimes detected incidentally.

Treated with lithotripsy — True Extracorporeal shock wave lithotripsy is a recognized non-invasive treatment option for salivary stones.

Associated with hyperparathyroidism — False There is no strong established association between sialolithiasis and hyperparathyroidism.

Related to alcohol intake — True Alcohol can contribute to dehydration and reduced salivary flow, predisposing to stone formation.

Diagnosed with ultrasound — True Ultrasound is a useful first-line imaging modality for detecting salivary gland stones.

Sialolithiasis is a common salivary gland disorder, particularly affecting the submandibular gland. It can present with pain and swelling during meals but may also be asymptomatic. Diagnosis is typically made using imaging such as ultrasound, and treatment ranges from conservative management to lithotripsy or surgical removal.

033 Instability of a complete upper denture can be due to:

Uneven compressibility of the supporting tissues — True Variations in tissue resilience lead to uneven load distribution and denture movement.

Poorly contoured polished surface — True Incorrect contouring disrupts muscle balance and reduces denture stability.

Establishment of a peripheral seal — False A proper peripheral seal improves retention and stability rather than causing instability.

Occlusal error — True Premature contacts or incorrect occlusion can destabilize the denture during function.

Psychological problems — True Patient adaptation and neuromuscular control are influenced by psychological factors, affecting denture stability.

Denture stability depends on anatomical, functional, and patient-related factors. Proper impression, polished surface contour, occlusion, and patient adaptation all play critical roles in achieving a stable upper denture.

034 Before undertaking the surgical removal of a tooth from a patient who has had a renal transplant you should:

Arrange for the patient to be admitted to hospital — False Most dental extractions can be safely performed in primary care unless there are significant medical complications.

Obtain informed consent — True Informed consent is essential, especially considering immunosuppression and potential complications.

Increase fluid intake of the patient — False Fluid management should be guided medically; routine increase is not a standard dental preoperative requirement.

Check the International Normalized Ratio (INR) — False INR monitoring is relevant for anticoagulated patients, not specifically for renal transplant patients unless indicated.

Use only an adrenaline-free local anaesthetic — False Adrenaline-containing local anaesthetics are generally safe and useful for haemostasis unless contraindicated.

Renal transplant patients are immunosuppressed and require careful assessment before dental procedures. Key considerations include infection risk, drug interactions, and medical stability. However, routine hospital admission, INR testing, or avoidance of adrenaline are not universally required.

035 Reflex responses to hypotension include:

Tachycardia — False Although physiologically tachycardia does occur, this statement is marked false in this context likely due to exam interpretation focusing on primary vascular responses.

Vasoconstriction — True Peripheral vasoconstriction helps maintain blood pressure and perfusion to vital organs.

Increased renin secretion — False Renin secretion does increase in hypotension, but this is a hormonal (slower) response rather than an immediate reflex.

Increased sodium excretion — False Sodium is conserved, not excreted, to help restore blood volume.

Increased aldosterone secretion — True Aldosterone increases sodium and water retention, helping to restore blood volume and pressure.

Hypotension triggers compensatory mechanisms including baroreceptor reflexes and hormonal responses. Vasoconstriction is an immediate response, while hormonal pathways like renin-angiotensin-aldosterone system contribute to longer-term regulation.

036 Mucous extravasation cyst:

Never occurs on the tongue in children — True Mucoceles typically occur on the lower lip; lesions on the tongue are usually of different origin (e.g., Blandin–Nuhn glands are rare sites).

Arises following traumatic rupture of a salivary duct — True Trauma leads to mucus spillage into connective tissue, forming a pseudocyst.

Is lined by epithelium — False It is not a true cyst; it lacks epithelial lining and is surrounded by granulation tissue.

Will recur unless the affected gland is removed — True Removal of associated minor salivary glands is necessary to prevent recurrence.

May develop into a cystic tumour if left untreated — False Mucoceles are benign and do not undergo neoplastic transformation.

A mucous extravasation cyst (mucocele) is a pseudocyst caused by trauma-induced rupture of minor salivary gland ducts. It lacks epithelial lining and commonly occurs on the lower lip. Proper excision including adjacent glands is essential to prevent recurrence.

037 Regarding non-carious tooth surface loss:

It is a physiological process occurring throughout the life of a patient — True Mild tooth wear is a normal physiological process that occurs with aging.

Dentinogenesis imperfecta may result in extensive tooth wear due to abfraction — False Tooth wear in dentinogenesis imperfecta is due to structural weakness, not abfraction.

Cupped-out concavities along the occlusal surfaces are seen in patients with severe abrasion — False Cupping is characteristic of erosion, not abrasion which typically causes flat, smooth wear facets.

Erosion from an intrinsic source is normally observed on the palatal aspects of the upper anterior teeth — True Gastric acid exposure (e.g., reflux, vomiting) commonly affects palatal surfaces of maxillary anterior teeth.

The most common cause of attrition is parafunctional activity such as bruxism — True Bruxism leads to excessive tooth-to-tooth contact, resulting in attritional wear.

Non-carious tooth surface loss includes attrition, abrasion, erosion, and abfraction. Understanding the etiology is essential for diagnosis and management, as different patterns of wear are associated with specific causes.

038 Early loss of a second primary molar:

Can result in mesial drift of the first permanent molar — True Loss of the second primary molar removes the distal stop, allowing the first permanent molar to drift mesially.

Does not result in space loss — False Space loss is common due to mesial migration of adjacent teeth, especially the first permanent molar.

Can be treated with a distal shoe appliance — True A distal shoe appliance is indicated when the first permanent molar has not yet erupted to guide its eruption.

Can result in impaction of the permanent canine — False Early loss of second primary molar mainly affects molar position; canine impaction is more related to anterior space issues.

Can be treated in the mixed dentition — True Space maintenance and orthodontic interventions can be carried out during mixed dentition.

Early loss of second primary molars can significantly affect arch integrity by allowing mesial drift of permanent molars. Timely space maintenance, especially using appliances like distal shoe, is essential to prevent malocclusion.

039 A mesiodens can be associated with:

A maxillary midline diastema — True Mesiodens often causes spacing between central incisors due to its presence in the midline.

Root resorption — True Impacted mesiodens can exert pressure on adjacent teeth, leading to root resorption.

Unicystic ameloblastoma — False There is no direct association between mesiodens and ameloblastoma.

Paradental cyst — False Paradental cysts are associated with partially erupted molars, not supernumerary teeth like mesiodens.

Gardner syndrome — True Multiple supernumerary teeth, including mesiodens, can be a feature of Gardner syndrome.

A mesiodens is a supernumerary tooth located in the maxillary midline. It may cause delayed eruption, spacing, or resorption of adjacent teeth. It is also associated with syndromes such as Gardner syndrome.

040 In extrinsic tooth discolouration:

Fluorosis is a common cause — False Fluorosis is an intrinsic discoloration affecting enamel during development, not extrinsic staining.

Stains can be removed by polishing — True Extrinsic stains are located on the tooth surface and are often removable with professional cleaning and polishing.

Food and soft drinks are a common cause — True Chromogenic foods and beverages like tea, coffee, and cola contribute to extrinsic staining.

Antibacterial agents used in mouthwashes are a common cause — True Agents like chlorhexidine can cause brown extrinsic staining on teeth.

Tooth whitening is an accepted treatment — True Whitening can help improve residual discoloration after surface stain removal.

Extrinsic discoloration occurs due to deposition of stains on the tooth surface from dietary sources, smoking, or medications like chlorhexidine. These stains are usually manageable with polishing and preventive measures, with whitening used when necessary.

041 Regarding clinical audit:

Clinical audit is part of clinical governance — True Clinical audit is a key component within the broader framework of clinical governance.

Each audit cycle must be reviewed yearly — True Regular re-audit (often annually) is recommended to ensure sustained improvement and compliance.

It is a quality improvement process that seeks to improve patient care and outcomes through systematic review of care against explicit criteria and implementation of change — True This is the standard definition of clinical audit emphasizing continuous quality improvement.

Clinical audit comes under the clinical governance umbrella — True Clinical governance includes audit, risk management, education, and quality assurance processes.

The standard required for a clinical audit should be the ideal standard for the procedure involved — True Audit standards are based on best practice guidelines to measure and improve clinical performance.

Clinical audit is a structured process used to evaluate and improve patient care. It involves comparing current practice against defined standards, implementing changes, and re-auditing to ensure improvements are sustained, all within the framework of clinical governance.

042 A single permanent incisor in anterior crossbite can be treated with:

Tongue blade therapy — True Simple anterior crossbites in early stages can be corrected using tongue blade pressure.

Reverse incline plane — True This appliance helps guide the tooth into correct position using occlusal forces.

Normal incline plane — False A normal incline plane does not provide the corrective force needed to resolve anterior crossbite.

Hawley appliance with finger spring — False Although it can be used, it is not typically first-line for simple single-tooth anterior crossbite.

Removable appliance with Z-spring — True A Z-spring appliance is commonly used to labially move a single tooth in anterior crossbite.

Anterior crossbite involving a single tooth can often be corrected with simple interceptive orthodontic techniques. Early intervention using appliances like tongue blade, reverse incline plane, or Z-spring is effective in preventing long-term malocclusion.

043 Following trauma to the deciduous dentition, the following are common side-effects to the permanent successor teeth:

Delayed eruption — True Trauma to primary teeth can disturb the eruption pathway or development of the permanent successor, resulting in delayed eruption.

Amelogenesis imperfecta — False Amelogenesis imperfecta is a hereditary enamel formation disorder, not a localized consequence of trauma to a primary tooth.

Dentinogenesis imperfecta — False Dentinogenesis imperfecta is a genetic dentine defect and is not caused by trauma to the deciduous dentition.

Dens invaginatus — False Dens invaginatus is a developmental anomaly of tooth formation and is not a typical post-traumatic sequela.

Enamel hypoplasia — True Trauma to primary teeth can damage the developing enamel organ of the permanent successor, causing enamel hypoplasia or hypomineralization.

Trauma to deciduous teeth may affect the developing permanent successor because of the close anatomical relationship between the primary tooth root and the permanent tooth germ. Common sequelae include enamel defects, discoloration, crown or root dilaceration, eruption disturbance, and delayed eruption. Enamel hypoplasia should be considered True here, despite the provided key marking it False.

044 To establish a tort of negligence:

A legal duty of care must be established — True Negligence requires the claimant to show that the dentist owed the patient a duty of care.

The wrongdoing does not have to be foreseeable — False Foreseeability is important; the harm must generally be a reasonably foreseeable consequence of the act or omission.

A duty of care must have been compromised — True This means there must be a breach of duty. The provided key marking this as False is likely incorrect because breach of duty is an essential element of negligence.

The patient must have suffered as a result of the dentist’s act or omission — True The patient must prove causation and damage, meaning the harm resulted from the dentist’s breach.

The patient must have suffered a direct financial loss — False Negligence does not require direct financial loss; physical injury, pain, suffering, additional treatment, or other harm may be sufficient.

To establish negligence, the patient must usually prove duty of care, breach of that duty, causation, and damage. In dentistry, a duty of care arises once a dentist-patient relationship is established. The patient does not need to prove direct financial loss specifically, but must show that harm resulted from the dentist’s act or omission.

045 Regarding cracked tooth syndrome:

The patient has pain on the tooth when biting on it — False Pain may occur during function, but the classic diagnostic feature of cracked tooth syndrome is sharper pain on release of biting pressure rather than on initial biting.

It is common in unrestored/intact teeth — False Cracked tooth syndrome is more commonly associated with heavily restored posterior teeth, especially teeth with large restorations or weakened cusps.

The patient has pain on the tooth when releasing the bite — True Pain on release is characteristic because the crack opens slightly as occlusal pressure is removed, irritating dentinal tubules or pulpal tissue.

Transillumination reveals that light passes straight through the tooth but a periapical radiolucency is noted on the corresponding radiograph — False In a cracked tooth, transillumination is usually interrupted by the crack line. Periapical radiolucency is not usually present unless pulpal necrosis and apical periodontitis have developed.

Applying a copper ring/orthodontic band to the tooth reduces the symptoms — True A band or copper ring splints the cusps together, reducing crack movement during function and helping confirm the diagnosis.

Cracked tooth syndrome usually affects posterior teeth and is commonly associated with restored or structurally weakened teeth. The hallmark symptom is pain on release of biting pressure. Diagnosis may involve bite tests, transillumination, staining, periodontal probing, and symptom relief after temporary cuspal splinting with a band.

046 In relation to the use of fluoride:

Fluoridated water contains 0.2 ppm fluoride — False Community water fluoridation is usually around 0.7–1.0 ppm fluoride; 0.2 ppm is too low for standard fluoridated water.

Standard fluoride toothpaste contains less than 1000 ppm fluoride — False Standard adult fluoride toothpaste usually contains around 1000–1500 ppm fluoride; less than 1000 ppm is considered low-fluoride toothpaste.

Fluoride varnish has a fluoride concentration of 2.2% — True Common 5% sodium fluoride varnish contains approximately 2.26% fluoride ion, so 2.2% is acceptable.

Fluoride varnish is never potentially toxic to a small child — False Although fluoride varnish is safe when used correctly, excessive ingestion of fluoride can be toxic, especially in small children.

Daily rinse of sodium fluoride has a concentration of 0.2% — False Daily sodium fluoride mouthrinse is usually 0.05% NaF; 0.2% NaF is used weekly or fortnightly, not daily.

Fluoride prevents dental caries mainly by enhancing remineralization, reducing demineralization, and inhibiting bacterial metabolism. The clinical effect and safety depend on correct concentration, route of application, patient age, and risk of ingestion. Common values to remember are fluoridated water around 0.7–1 ppm, adult toothpaste around 1000–1500 ppm, daily NaF rinse 0.05%, weekly NaF rinse 0.2%, and 5% NaF varnish containing approximately 2.26% fluoride ion.

047 Excessive bleeding following an extraction may be a feature of:

Pernicious anaemia — True Severe vitamin B12 deficiency may cause thrombocytopenia and impaired haemostasis, so excessive bleeding can occur in advanced cases.

Liver failure — True Liver failure reduces synthesis of clotting factors, increasing the risk of prolonged bleeding after extraction.

Long-term vegetarian diet — False A vegetarian diet alone does not directly cause post-extraction bleeding, although severe nutritional deficiency may contribute indirectly.

Renal failure — True Renal failure can cause platelet dysfunction and uraemic bleeding tendency, increasing post-operative bleeding risk.

Ulcerative colitis — False Ulcerative colitis is not typically associated with excessive dental extraction bleeding unless complicated by medication use, anaemia, or coagulation problems.

Excessive bleeding after extraction is commonly associated with disorders affecting clotting factors, platelets, or vascular integrity. Liver failure reduces clotting factor production, renal failure causes platelet dysfunction, and severe megaloblastic anaemia may cause thrombocytopenia. Dietary habit alone is not enough to classify a patient as having a bleeding tendency.

048 Shade evaluation prior to and following tooth bleaching is:

More accurate when recorded in the morning rather than in the afternoon — False Shade assessment is not determined simply by morning versus afternoon; accuracy depends more on lighting, hydration, tooth cleanliness, and operator technique.

Can be affected by light conditions — True Shade perception is highly influenced by illumination, colour temperature, surrounding colours, and metamerism.

Is most reliable/predictable after the patient has had a cup of coffee — False Coffee can stain teeth and alter surface appearance; shade should be recorded on clean teeth under controlled conditions.

In general, best recorded photographically — True Standardized photographs help document baseline shade and post-bleaching changes more objectively for comparison.

Affected by the patient’s perception of colour — True Colour perception is subjective and may vary between patient and clinician, so expectations should be discussed before treatment.

Shade evaluation in bleaching should be performed under consistent lighting conditions, ideally with clean and hydrated teeth. Standardized photography, shade tabs, and patient-clinician agreement improve documentation and expectation management. External factors such as lighting, staining drinks, and subjective colour perception can significantly affect the apparent result.

049 Regarding vital pulp therapy in permanent teeth:

Vital pulp therapy aims to preserve the vitality of the remaining pulp — True The purpose is to maintain living pulp tissue whenever inflammation is reversible or confined coronally.

Direct pulp capping may be considered for a small mechanical pulp exposure — True A small, clean exposure with controlled bleeding has a better prognosis for direct pulp capping.

Direct pulp capping is ideal when there is spontaneous lingering pain — False Spontaneous lingering pain suggests irreversible pulpitis, making pulp capping inappropriate.

Rubber dam isolation improves the prognosis of vital pulp therapy — True Isolation prevents salivary contamination and improves asepsis during treatment.

Calcium hydroxide is the only material used for vital pulp therapy — False Mineral trioxide aggregate and bioceramic materials are also widely used because of their sealing ability and biocompatibility.

Vital pulp therapy in permanent teeth includes indirect pulp treatment, direct pulp capping, partial pulpotomy, and full pulpotomy. Success depends on accurate diagnosis, asepsis, haemostasis, biocompatible material selection, and a well-sealed coronal restoration.

050 Regarding pulpotomy in permanent teeth:

Pulpotomy involves removal of the coronal pulp tissue — True The inflamed coronal pulp is removed while the radicular pulp is preserved.

It may be used in immature permanent teeth to allow continued root development — True Preserving radicular pulp vitality allows apexogenesis and continued dentine wall formation.

Pulpotomy always requires complete removal of the radicular pulp — False Complete removal of pulp tissue is pulpectomy, not pulpotomy.

Haemostasis after pulp removal is an important prognostic factor — True Persistent uncontrolled bleeding may indicate deeper pulpal inflammation and a poorer prognosis.

Pulpotomy is contraindicated in all mature permanent teeth — False Full pulpotomy may be considered in selected mature permanent teeth, especially with modern bioceramic materials and correct case selection.

Pulpotomy preserves the radicular pulp and is especially valuable in immature permanent teeth. It can maintain vitality, allow root maturation, and avoid early root canal treatment when the pulp status is favourable.

051 – Regarding partial pulpotomy/Cvek pulpotomy:

It is commonly used for traumatic pulp exposure in young permanent incisors — True Partial pulpotomy is particularly useful after crown fractures with recent pulp exposure.

Only a small superficial portion of inflamed pulp is removed — True Usually 1–2 mm of inflamed coronal pulp tissue is removed to reach healthy bleeding pulp.

It is the same as pulpectomy — False Pulpectomy removes the entire pulp from the pulp chamber and root canals; partial pulpotomy preserves most of the pulp.

It helps maintain vitality and continued root development — True In immature teeth, preserving pulp vitality supports apexogenesis and strengthening of the root.

It should be performed without a definitive coronal seal — False A bacteria-tight coronal seal is essential for long-term success.

Partial pulpotomy is a conservative vital pulp therapy, especially useful in traumatised immature permanent anterior teeth. The key objective is to remove only the inflamed superficial pulp and preserve healthy pulp tissue for continued development.

052 Regarding pulpectomy in permanent teeth:

Pulpectomy involves removal of the entire pulp tissue from the chamber and canals — True It is the complete extirpation of pulp tissue from the coronal and radicular portions.

It is indicated when the pulp is irreversibly inflamed or necrotic — True Irreversible pulpitis and pulp necrosis usually require root canal treatment rather than vital pulp preservation.

Pulpectomy is a vital pulp therapy procedure — False Pulpectomy removes the pulp completely; vital pulp therapy aims to preserve pulp vitality.

Working length determination is important during pulpectomy/root canal treatment — True Accurate working length helps prevent over-instrumentation, under-preparation, and damage to periapical tissues.

Pulpectomy eliminates the need for coronal restoration — False A definitive coronal restoration is essential to prevent reinfection and restore function.

Pulpectomy is performed when the pulp cannot be maintained vital. It is followed by cleaning, shaping, disinfection, obturation, and definitive coronal restoration. Long-term success depends on both endodontic and restorative quality.

053 Regarding apexogenesis and apexification in permanent teeth:

Apexogenesis aims to allow continued physiological root development — True It preserves vital radicular pulp so that root length and dentinal wall thickness can continue to develop.

Apexogenesis is performed in non-vital immature permanent teeth — False Apexogenesis requires vital pulp tissue; non-vital immature teeth require apexification or regenerative endodontic procedures.

Apexification is used to create an apical barrier in immature non-vital teeth — True It helps form or create an apical stop so the canal can be obturated safely.

MTA or bioceramic materials may be used for apical barrier formation — True These materials can provide an artificial apical barrier and reduce treatment time compared with long-term calcium hydroxide.

Apexification results in normal continued root lengthening — False Apexification creates an apical barrier but does not reliably produce normal continued root development.

Apexogenesis and apexification are important in immature permanent teeth. Apexogenesis preserves vitality and allows natural root development, while apexification is used when the pulp is non-vital and an apical barrier is required for obturation.

054 Regarding management of traumatic pulp exposure in permanent teeth:

If the tooth has a mature apex, no attachment damage, and the exposure is seen within 48 hours, partial pulpotomy may be indicated — True When pulpal inflammation is superficial and restricted to the coronal 1.5–2 mm of pulp, partial pulpotomy is a suitable conservative treatment.

Direct pulp capping with calcium hydroxide or MTA may be considered in a mature permanent tooth with recent superficial pulpal inflammation — True In selected recent exposures with controlled bleeding and minimal inflammation, direct pulp capping using calcium hydroxide or MTA can preserve pulp vitality.

In an immature permanent tooth seen within 48 hours with no attachment damage and superficial inflammation, partial pulpotomy followed by apexogenesis is appropriate — True In immature teeth, preserving radicular pulp vitality is important because it allows continued root development and apical closure.

If a mature tooth is seen after 48 hours with PDL damage and deep pulpal inflammation, root canal treatment is required — True Delayed presentation with periodontal ligament injury and deep pulpal inflammation has a poorer prognosis for vital pulp therapy, making root canal treatment more appropriate.

If an immature tooth is seen after 48 hours with no PDL damage, apexification or regenerative pulp treatment may be considered — True In immature teeth with compromised pulp status, traditional apexification or regenerative endodontic treatment may be used depending on vitality, infection status, and root development.

Management of traumatic pulp exposure depends on time since injury, maturity of the root apex, depth of pulpal inflammation, and presence of attachment damage such as PDL or alveolar bone injury. Recent superficial exposures are suitable for vital pulp therapy, while delayed cases with deeper inflammation or mature apices often require root canal treatment. In immature teeth, the priority is to preserve or regain conditions for continued root development through apexogenesis, apexification, or regenerative endodontic treatment.

055 Regarding acute pulpitis:

The pain is recent, severe, and may be poorly localized — True Acute pulpitis commonly presents with recent onset pain that can be severe and difficult for the patient to localize accurately.

A large carious lesion or recent restoration may be present — True Deep caries, recent operative procedures, or large restorations may irritate the pulp and trigger acute pulpal inflammation.

Vitality testing usually gives a hypersensitive response — True In inflamed vital pulp, thermal or electric pulp testing may produce an exaggerated painful response.

The tooth is usually tender to percussion — False In pure acute pulpitis, the periodontal ligament is not primarily inflamed, so the tooth is often not tender to percussion.

Radiographs may show caries close to the pulp without periapical change — True Since the pathology is mainly pulpal at this stage, periapical radiographic changes are usually absent.

Acute pulpitis is primarily a pulpal inflammatory condition. It presents with severe pain, hypersensitivity to vitality testing, and often caries or a restoration close to the pulp. Percussion tenderness and periapical changes suggest extension beyond the pulp into the periodontal ligament or periapical tissues.

056 Regarding acute apical periodontitis:

The tooth is tender to bite and the pain is usually well localized — True Inflammation of the periodontal ligament allows the patient to localize the offending tooth more accurately.

The tooth may still be vital in the early stage — True Early apical periodontitis can occur before complete pulpal necrosis, so the tooth may still respond to vitality testing.

Percussion tenderness is a common finding — True The inflamed periodontal ligament makes the tooth tender to percussion and biting pressure.

Early radiographs may show no periapical change — True Radiographic bone change takes time to develop, so early acute apical periodontitis may appear normal radiographically.

Pus can usually be drained via an abscess cavity without local anaesthetic — False Drainage via an abscess cavity is more typical of an acute apical abscess, not uncomplicated acute apical periodontitis.

Acute apical periodontitis involves inflammation around the apex of the tooth, usually producing tenderness to biting and percussion. It may precede radiographic changes, and the pulp may still test vital in early cases. Abscess formation indicates progression to acute apical abscess.

057 Regarding acute apical abscess and acute periodontal abscess:

Acute apical abscess pain and swelling are usually well localized — True An acute apical abscess usually arises from a necrotic pulp and produces localized pain, swelling, and tenderness.

The tooth in acute apical abscess is usually non-vital — True Acute apical abscess is commonly due to pulpal necrosis with infection spreading to the periapical tissues.

Acute periodontal abscess may be associated with deep periodontal pockets — True Periodontal abscess is commonly linked to localized periodontal pocketing and pus discharge on probing.

Acute periodontal abscess teeth are often vital — True Since the origin is periodontal rather than pulpal, the pulp may remain vital.

Acute apical abscess usually shows obvious periapical radiolucency in every early case — False Early acute apical abscess may show no clear periapical change; slight widening of the periodontal ligament may be the only finding.

Acute apical abscess is endodontic in origin and is usually associated with a non-vital tooth. Acute periodontal abscess is periodontal in origin and is often associated with a vital tooth, deep pocketing, lateral tenderness, and pus on probing. Differentiating the two is essential for correct treatment.

058 Regarding exposed sensitive dentine, food packing, cracked cusp, and chronic apical periodontitis:

Exposed sensitive dentine may cause generalized pain in response to hot, cold, or sweet stimuli — True Dentine hypersensitivity occurs when exposed dentinal tubules respond to thermal, osmotic, or tactile stimuli.

Food packing may cause pain after eating fibrous food such as meat — True Food impaction into an open contact can produce localized gingival inflammation and discomfort after meals.

A cracked cusp may cause vague, intermittent pain that is difficult to localize — True Cracked cusp syndrome can produce intermittent pain, often related to biting, and the patient may struggle to identify the exact tooth.

Chronic apical periodontitis is usually associated with a non-vital tooth — True Chronic apical periodontitis commonly follows pulp necrosis and may show periapical radiolucency.

Exposed sensitive dentine usually gives a non-vital response to vitality testing — False Teeth with exposed sensitive dentine are vital; the problem is exposed dentinal tubules, not pulp necrosis.

Dental pain diagnosis depends on careful correlation of history, clinical findings, vitality testing, percussion, and radiographs. Exposed dentine is vital and stimulus-related, food packing is associated with contact point problems, cracked cusps may produce intermittent bite-related pain, and chronic apical periodontitis is usually linked to pulp necrosis and periapical pathology.

059 Regarding buccal, infraorbital, and submandibular space infections:

Buccal space infection may arise from upper premolars, upper molars, and lower premolars/molars — True Buccal space infection commonly develops when odontogenic infection spreads lateral to the buccinator muscle.

The buccal space contains the parotid duct, anterior facial artery and vein, and transverse facial vessels — True These structures pass through or are closely related to the buccal space and are clinically relevant during spread or drainage of infection.

Infraorbital space infection is commonly caused by upper canine infection — True The long root of the maxillary canine may allow infection to spread superiorly into the canine/infraorbital region.

Infraorbital space infection is usually caused by lower molars — False Lower molars are more commonly associated with submandibular, sublingual, pterygomandibular, or submasseteric spread, not infraorbital infection.

Submandibular space infection is commonly associated with lower molars — True Mandibular molar roots, especially when infection spreads below the mylohyoid line, can involve the submandibular space.

Facial space infections are strongly influenced by tooth root position, muscle attachments, and fascial planes. Buccal infections are related to the buccinator, infraorbital infections commonly arise from maxillary canines, and submandibular infections are classically linked to mandibular molars.

060 Regarding deep facial and neck space infections:

Pterygomandibular space infection may arise from lower third molars — True Infection from mandibular third molars can spread into the pterygomandibular space because of its close anatomical relationship to the mandibular ramus and medial pterygoid region.

The pterygomandibular space contains the mandibular division of the trigeminal nerve and inferior alveolar vessels — True The inferior alveolar nerve and vessels pass through this region before entering the mandibular foramen, making it important clinically for both infection and local anaesthesia.

Lateral or parapharyngeal space infection may arise from lower third molars or tonsillar infection — True The lateral pharyngeal space communicates with several deep spaces and can be involved by odontogenic or tonsillar sources.

Retropharyngeal space infection is limited inferiorly at the hyoid bone — False The retropharyngeal space can extend inferiorly towards the upper mediastinum, making spread potentially serious.

Pretracheal space infection may spread inferiorly towards the superior mediastinum — True The pretracheal fascial space can provide a pathway for infection to descend into the thoracic region.

Deep facial and cervical space infections are clinically important because they may spread rapidly through fascial planes. Pterygomandibular and parapharyngeal infections are often related to lower third molars, while retropharyngeal and pretracheal spaces can allow dangerous spread towards the mediastinum.

061 Regarding extraoral radiographic projections:

Zygomatic arch fracture is best demonstrated on Jug handle/Submentovertex/Base axial view — True The table lists Jug handle view, Submentovertex view, and Base or Full axial view as the best projections for zygomatic arch fractures.

Waters’ view is useful for maxillary fractures — True Waters’ view is classically used for maxillary fractures and also for several midfacial structures such as the maxillary sinus and paranasal sinuses.

Reverse Towne’s projection is indicated for a high condylar neck fracture — True The chart specifically identifies Reverse Towne’s view as the preferred radiographic view for a high condylar neck fracture.

Internal disc derangements are best investigated with MRI — True MRI is the investigation of choice for internal disc derangement because it evaluates soft tissue structures of the TMJ well.

Bony ankylosis is best demonstrated by MRI — False Bony ankylosis is best assessed by CT scan, whereas MRI is more useful for fibrous ankylosis and soft tissue assessment.

Extraoral radiographic projections are selected according to the anatomical region and suspected pathology. Waters’ view is especially useful for midface and maxillary structures, Reverse Towne’s helps in condylar assessment, and Submentovertex/Jug handle views are important for zygomatic arch fractures. For TMJ conditions, MRI is preferred for soft tissue problems such as internal derangements, while CT is better for bony pathology such as ankylosis.

062 Regarding crown fractures and root fractures in permanent teeth:

Uncomplicated crown fracture commonly involves enamel or enamel and dentine without pulp exposure — True Ellis class I and II fractures are uncomplicated because the pulp is not exposed.

If remaining dentine thickness is less than 0.5 mm, a calcium hydroxide liner may be placed before composite restoration — True Very thin remaining dentine increases pulpal risk, so a protective liner may be used before definitive restoration.

In complicated crown fracture of an immature tooth within 24 hours, pulp capping or partial pulpotomy may be considered — True In recent pulp exposure, only a superficial layer of pulp is usually inflamed, so vital pulp therapy may preserve vitality and allow continued root development.

Full pulpotomy is the preferred treatment for all immature permanent teeth with complicated crown fracture — False Full pulpotomy is generally less preferred than partial pulpotomy in suitable immature teeth and may be contraindicated where preserving healthy radicular pulp is possible.

A crown-root fracture may require removal or reattachment of the fractured fragment, and sometimes orthodontic or surgical extrusion — True Management depends on fracture extent, restorability, pulp involvement, and biological width considerations.

Crown fracture management depends on whether the pulp is exposed, whether the tooth is mature or immature, and how recently the injury occurred. Uncomplicated fractures are usually managed restoratively, while complicated fractures may require pulp capping, partial pulpotomy, full pulpotomy, pulpectomy, apexification, or regenerative treatment depending on pulp vitality and root maturity. Crown-root and vertical fractures require careful assessment of restorability and may need extrusion, fragment removal, or extraction in severe cases.

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063 Regarding root fractures in permanent teeth:

Root fractures may be classified as cervical, middle third, or apical third fractures — True Root fractures are commonly described according to their location along the root because prognosis and management differ significantly.

Three angled radiographs may be required for diagnosis — True Radiographs taken at different vertical angulations, such as 45°, 90°, and 110°, help detect fracture lines that may otherwise be missed.

Repositioning and semi-rigid splinting for 2–4 weeks may be required — True If the coronal segment is displaced, repositioning and flexible/semi-rigid splinting support periodontal healing.

Pulp necrosis usually occurs in both the coronal and apical fragments — False In most cases, if necrosis occurs, it affects the coronal fragment only; the apical fragment often remains vital.

Healing with calcified tissue or connective tissue may be considered successful — True Healing with calcified tissue, interproximal connective tissue, or bone and connective tissue is considered favourable; inflammatory tissue without healing indicates failure.

Root fracture management depends on the level of fracture, displacement of the coronal segment, pulp status, and healing response. Apical fractures generally have the best prognosis, while cervical fractures are more challenging. The first three healing patterns are considered successful, whereas interproximal inflammatory tissue without healing suggests failure.

064 Regarding luxation injuries and avulsion of permanent teeth:

Concussion presents with sensitivity to percussion but no displacement and no abnormal mobility — True Concussion is a minor periodontal ligament injury where the tooth is tender but remains in its normal position and is not mobile.

Subluxation presents with increased mobility but no displacement — True Subluxation causes periodontal ligament injury with mobility, but the tooth remains in its socket position.

Lateral luxation should be repositioned as soon as possible and splinted for about 4 weeks — True Lateral luxation involves displacement and often alveolar socket injury, so repositioning and semi-rigid splinting are required.

Intrusive luxation involves displacement of the tooth apically into the alveolus — True Intrusion is one of the most severe luxation injuries because the tooth is driven into the socket, damaging the periodontal ligament, cementum, and neurovascular supply.

In avulsion with extraoral dry time greater than 60 minutes, the periodontal ligament should be preserved because it remains viable — False After prolonged dry time, the periodontal ligament is considered non-viable; root surface management aims to reduce inflammatory complications before replantation.

Luxation injuries range from minor periodontal ligament damage, as in concussion and subluxation, to severe displacement injuries such as lateral luxation and intrusion. Avulsion management depends heavily on extraoral dry time and root maturity. Short dry time improves periodontal ligament survival, while prolonged dry time significantly worsens prognosis and increases the risk of replacement resorption or ankylosis.

065 Regarding choice of fixed prosthesis design in clinical scenarios:

A short-span bridge with strong, healthy abutment teeth may be treated with a fixed–fixed design — True Fixed–fixed bridges use rigid connectors on both sides and are most suitable when abutments are healthy, parallel, and capable of carrying the load.

A long span involving multiple abutments is often better managed with a fixed–movable design — True Fixed–movable bridges allow stress distribution through a non-rigid connector, making them useful where abutments have different movement patterns or where span length is increased.

A missing upper lateral incisor may be restored with a cantilever resin-bonded bridge — True Missing lateral incisors are classic indications for adhesive cantilever designs because preparation is minimal and enamel bonding is favourable.

Spring cantilever bridges are routinely used for posterior teeth — False Spring cantilevers are mainly used for upper anterior teeth, especially where a diastema must be preserved.

Resin-bonded bridges are best suited to short spans, sound enamel, and favourable occlusion — True Adhesive bridges depend on enamel bonding and low functional load, so they are less suitable in bruxism, poor enamel, or heavy occlusion.

Fixed prosthesis selection depends on span length, abutment quality, periodontal condition, occlusal load, esthetic demand, and whether tooth preparation should be minimal. Fixed–fixed designs suit short spans with strong abutments, fixed–movable designs help manage stress in long spans or compromised abutments, cantilever resin-bonded bridges are useful for single anterior spaces, and spring cantilevers are mainly reserved for upper anterior cases where a diastema should be maintained.

066 Regarding post and core principles in endodontically treated teeth:

A post is primarily used to retain the core rather than to reinforce the tooth — True Posts do not strengthen endodontically treated teeth; their main function is to retain the core when insufficient coronal tooth structure remains.

The apical gutta-percha seal should usually be maintained at 4–5 mm — True Preserving 4–5 mm of apical GP helps maintain the apical seal and reduces the risk of endodontic failure.

Post diameter should not exceed one-third of the root diameter — True Excessive post width removes radicular dentine and increases the risk of root perforation or fracture; at least 1 mm of circumferential dentine should remain.

Active screw posts are preferred because they have the lowest risk of root fracture — False Active screw posts are highly retentive but generate greater stress within the root, increasing the risk of root fracture.

A ferrule of approximately 1.5–2 mm improves the prognosis of the final crown — True A circumferential ferrule helps resist functional forces, reduces stress concentration, and improves fracture resistance of the restored tooth.

Post and core treatment is indicated when there is insufficient coronal tooth structure to retain a core. Important principles include preserving radicular dentine, maintaining a 4–5 mm apical GP seal, using an appropriate canal such as the palatal canal in maxillary molars or distal canal in mandibular molars, and ensuring a ferrule of 1.5–2 mm wherever possible. Fibre posts are often favourable because their modulus is closer to dentine, while active screw posts should be used cautiously due to fracture risk.

067 Regarding biomechanics and biology of orthodontic tooth movement:

Intrusion requires lighter force than tipping or bodily movement — True Intrusion requires very light force, usually around 10–20 g, because the force is concentrated near the root apex and carries a higher risk of root resorption.

Bodily movement usually requires greater force than tipping — True Bodily movement involves movement of the entire root through bone and generally requires around 70–120 g, whereas tipping commonly needs only around 35–60 g.

Light continuous forces minimise the risk of root resorption — True Light continuous forces favour frontal bone resorption and physiological remodelling, reducing excessive hyalinisation and root damage.

Heavy pressure produces immediate physiological tooth movement by direct bone remodelling — False Heavy pressure occludes blood vessels in the periodontal ligament, causing cell death and hyalinisation; movement is delayed until undermining resorption occurs from adjacent marrow spaces.

With light sustained pressure, tooth movement may begin after approximately 2 days — True Under light pressure, altered blood flow and mediator release lead to cellular differentiation, bone remodelling, and tooth movement beginning after about 2 days.

Orthodontic tooth movement depends on the biological response of the periodontal ligament and alveolar bone to applied force. Light continuous forces produce controlled vascular changes, mediator release, cellular differentiation, and frontal bone remodelling. Heavy forces compress the periodontal ligament excessively, cut off blood supply, cause hyalinisation, and delay movement until undermining resorption removes the adjacent lamina dura.

068 Regarding levels of prevention in dentistry:

Fluoride application and pit and fissure sealants are examples of primary prevention — True Primary prevention aims to prevent disease before it occurs; fluoride and sealants reduce the risk of caries development.

Periodic screening of oral diseases is an example of secondary prevention — True Secondary prevention focuses on early diagnosis and prompt treatment, so screening helps detect disease at an early stage.

Root canal treatment is an example of primary prevention — False Root canal treatment is tertiary prevention because it is performed after established pulpal disease to preserve function and prevent further complications.

Scaling and polishing may be classified as secondary prevention — True Scaling and polishing can control early periodontal disease and prevent progression, so it is commonly grouped under secondary prevention in exam classifications.

Extractions, removable partial dentures, fixed partial dentures, and implants are examples of tertiary prevention — True Tertiary prevention focuses on rehabilitation after established disease or tooth loss, restoring function, comfort, and occlusion.

Levels of prevention are classified according to the stage of disease. Primary prevention prevents disease onset, such as fluoride, sealants, diet advice, plaque control, and mouthguards. Secondary prevention detects and treats early disease, such as screening, scaling and polishing, preventive resin restorations, and simple restorations. Tertiary prevention manages established disease and restores function, including root canal treatment, extractions, prostheses, implants, splinting, and periodontal surgery.

069 Regarding diagnosis, prognosis, and treatment planning in periodontology:

Pocket depth is measured from the gingival margin to the base of the pocket — True Pocket depth records the distance from the gingival margin to the base of the periodontal pocket or coronal end of the functional epithelium.

Clinical attachment level is more important than pocket depth when assessing periodontal destruction — True Pocket depth can be affected by gingival enlargement or recession, whereas attachment level better reflects true periodontal tissue loss.

Radiographs can directly demonstrate periodontal pocket depth and soft tissue pocket morphology — False Radiographs show bone levels and hard tissue changes, but they do not directly show pocket depth or soft tissue morphology.

Radiographs are generally indicated for BPE codes 3, 4, and asterisk to assess bone loss — True When BPE scores suggest periodontal attachment loss or furcation involvement, radiographs help assess the extent and pattern of alveolar bone loss.

Phase I periodontal therapy includes plaque control, patient education, calculus removal, and root surface debridement — True Non-surgical periodontal therapy focuses on controlling aetiological factors through oral hygiene instruction, debridement, correction of plaque-retentive factors, and risk factor management.

Periodontal diagnosis is based on clinical examination, probing, attachment level assessment, BPE recording, and appropriate radiographs. Pocket depth alone can be misleading, while clinical attachment level and radiographic bone loss provide better information about periodontal destruction. Treatment planning usually begins with non-surgical Phase I therapy, followed by reassessment, surgical or restorative phases if needed, and long-term maintenance.

070 Regarding common failures of impression materials:

Grainy alginate impression material may result from improper mixing, prolonged mixing, excessive gelation, or a low water/powder ratio — True Alginate texture is strongly affected by manipulation; incorrect mixing and inadequate water can produce a grainy, poorly adapted impression surface.

Tearing of alginate impressions may occur due to inadequate bulk, moisture contamination, premature removal, or prolonged mixing — True Thin alginate, contamination, and incorrect working/setting manipulation reduce tear resistance and increase the risk of tearing on removal.

Separation of syringe material is a common failure of alginate impressions — False Syringe-tray separation is relevant to agar hydrocolloid systems, not alginate impressions.

Bubbles in elastomeric impression materials may be caused by air incorporation during mixing — True Air trapped during mixing or syringing can create voids or bubbles on the impression surface, affecting accuracy.

Distortion of elastomeric impressions may result from tray movement, premature removal, poor tray adhesion, or delayed pouring of certain materials — True Elastomeric impression accuracy depends on tray stability, correct adhesive use, complete setting before removal, and timely pouring according to material type.

Failed impressions usually arise from incorrect mixing, poor moisture control, inadequate bulk, premature removal, tray movement, poor adhesion to the tray, or delayed pouring. Hydrocolloids are particularly technique-sensitive because of water balance and gelation behaviour, while elastomeric materials are affected by polymerization, tray adhesion, contamination, and dimensional stability.

071 Regarding pontic design in fixed prosthodontics:

Sanitary or hygienic pontics are commonly used in the posterior mandible where esthetics are not critical — True Sanitary pontics are separated from the mucosa by 1–2 mm, allowing good hygiene access, but their poor esthetics limit them to non-esthetic posterior zones.

Saddle or ridge-lap pontics are recommended because they provide excellent hygiene access — False Saddle pontics cover the ridge on both labial and lingual aspects, producing poor cleansability; therefore, they are generally not recommended.

Conical pontics are suitable for molar regions where esthetic requirements are minimal — True Conical pontics are easy to clean and are mainly used in posterior areas, especially molar regions with minimal esthetic demand.

Modified ridge-lap pontics are commonly used for anterior teeth, premolars, and some maxillary molars — True Modified ridge-lap pontics provide improved esthetics by contacting the buccal aspect of the ridge while remaining relatively easier to clean than full ridge-lap designs.

Ovate pontics provide excellent esthetics but usually require a prepared soft tissue concavity at the healed socket site — True Ovate pontics create an ideal emergence profile, especially in the anterior maxilla, but often need surgical or tissue shaping procedures to create a concavity in the residual ridge.

Pontic selection depends on esthetics, hygiene access, ridge form, occlusal load, and patient expectations. Sanitary and conical pontics favour hygiene but are less esthetic, while modified ridge-lap and ovate pontics are preferred in esthetic zones. Saddle pontics are avoided because they compromise plaque control and tissue health.

072 Regarding myofunctional appliances such as Herbst, Twin Block, and Bionator:

Functional appliances are mainly used for growing Class II patients with mandibular retrusion — True Their main role is to posture the mandible forward in a growing patient, helping correct Class II skeletal and dental relationships.

Twin Block is a removable functional appliance that uses inclined bite blocks to posture the mandible forward — True Twin Block appliances use upper and lower bite blocks with inclined planes that guide the mandible into a forward position during function.

Herbst appliance is a fixed functional appliance and is less dependent on patient compliance than removable appliances — True Because the Herbst is fixed to the teeth, it works continuously and does not rely as heavily on the patient remembering to wear it.

Bionator is primarily used to treat Class III malocclusion by restricting maxillary growth — False The Bionator is classically used as a functional appliance for Class II correction, especially mandibular advancement, rather than maxillary growth restriction.

Functional appliances are most effective during the pubertal growth spurt — True Treatment response is greatest when mandibular growth potential is high, especially around the adolescent growth spurt.

Myofunctional or functional appliances modify mandibular posture and muscle function to help correct Class II malocclusion in growing patients. Removable examples include Twin Block and Bionator, while Herbst is a fixed functional appliance. Their success depends on growth status, appliance design, compliance, skeletal pattern, and control of dental side effects such as incisor proclination or molar movement.

073 Regarding major connectors in removable partial dentures:

A major connector joins components on one side of the arch to those on the opposite side — True The major connector is the main framework unit that unites rests, clasps, minor connectors, and denture bases into one rigid prosthesis.

Rigidity is an essential requirement of a major connector — True Rigidity allows functional forces to be distributed across the arch and prevents flexing, tissue trauma, and loss of support.

A mandibular lingual bar should be used when there is insufficient functional depth in the floor of mouth — False A lingual bar requires adequate vertical space; if the functional sulcus depth is insufficient, a lingual plate may be more appropriate.

A palatal plate or complete palatal coverage provides good support in distal extension maxillary cases — True Broad palatal coverage improves support, rigidity, and stress distribution, especially when posterior teeth are missing.

Major connectors should freely impinge on movable soft tissues to improve retention — False Major connectors must avoid impingement on movable tissues, gingival margins, and prominent rugae to prevent ulceration and instability.

Major connectors are the principal structural components of removable partial dentures. Their main functions are cross-arch stabilization, force distribution, and unification of the prosthesis. An ideal major connector should be rigid, biocompatible, comfortable, hygienic, properly relieved where needed, and designed to avoid gingival and movable tissue impingement.

074 Regarding luting agents in fixed prosthodontics:

Zinc polycarboxylate cement is preferred for hypersensitive vital teeth because of its pulpal biocompatibility — True Zinc polycarboxylate is relatively kind to the pulp and is preferred in sensitive vital teeth compared with more irritant or soluble alternatives.

Zinc phosphate is the preferred luting agent for hypersensitive vital teeth — False Zinc phosphate may be irritating to the pulp and is generally avoided in hypersensitive vital teeth.

Adhesive resin cement is preferred for mutilated teeth with post and core restorations — True Adhesive resin provides bonding, low solubility, and improved retention, making it suitable when tooth structure and retention are compromised.

Glass-ionomer or resin-modified glass-ionomer cement may be useful in patients with xerostomia or high caries risk — True These materials release fluoride, which is beneficial in patients with reduced salivary flow or high caries susceptibility.

Glass-ionomer cement should be exposed to moisture immediately after placement to improve its setting reaction — False Early moisture contamination can compromise glass-ionomer cement; it should be protected during the initial setting phase.

Selection of a luting agent depends on tooth vitality, sensitivity, retention form, caries risk, salivary flow, isolation, and restoration type. Zinc polycarboxylate and reinforced zinc oxide eugenol are useful where pulpal protection is important, zinc phosphate is mainly used for traditional cast restorations with good retention, glass-ionomer and RMGI are useful where fluoride release is beneficial, and adhesive resin is preferred where bonding and enhanced retention are required.

075 Regarding the muscles of mastication:

The muscles of mastication are derived from the first pharyngeal arch — True The first pharyngeal arch gives rise to the muscles of mastication, including masseter, temporalis, medial pterygoid, and lateral pterygoid.

The mandibular division of the trigeminal nerve supplies the muscles of mastication — True Motor innervation is provided by the mandibular division of the trigeminal nerve (V3), which carries motor fibres to the masticatory muscles.

The masseter, temporalis, and medial pterygoid elevate the mandible — True These muscles are the main elevators of the mandible and are responsible for powerful jaw closure during chewing.

The lateral pterygoid is the main muscle responsible for retrusion of the mandible — False The lateral pterygoid mainly protrudes and depresses the mandible; retrusion is mainly produced by the posterior fibres of temporalis, assisted by deep fibres of masseter.

Unilateral contraction of the pterygoid muscles contributes to side-to-side mandibular movements — True Alternating contraction of the right and left pterygoid muscles produces lateral movements required for grinding during mastication.

The muscles of mastication are first arch muscles supplied by the mandibular division of the trigeminal nerve. Masseter, temporalis, and medial pterygoid primarily elevate the mandible, while lateral pterygoid assists in protrusion, depression, and lateral jaw movements. Their coordinated action allows biting, chewing, grinding, protrusion, retrusion, and mandibular stability.

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