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Afghanistan Dental Exit Exam study materials
Afghanistan Dental Exit Exam study resources

Afghanistan Dental Exit Exam practice questions

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Question 1Oral Anatomy, Histology, and Physiology

Which permanent tooth typically erupts first in the oral cavity?

  1. Mandibular central incisor
  2. Maxillary central incisor
  3. Mandibular first molar Correct answer.
  4. Maxillary first molar

Explanation

The permanent mandibular first molar erupts at roughly 6 years of age and is usually the first permanent tooth to appear, just before the mandibular central incisors. It forms the cornerstone of the developing arch.

Question 2Oral Anatomy, Histology, and Physiology

Enamel is formed by which type of cell?

  1. Ameloblast Correct answer.
  2. Fibroblast
  3. Odontoblast
  4. Cementoblast

Explanation

Ameloblasts are the specialized epithelial cells of the enamel organ that secrete enamel matrix and direct its mineralization. They are lost after tooth eruption, so enamel cannot regenerate.

Question 3Oral Anatomy, Histology, and Physiology

Which salivary gland produces the largest volume of saliva under resting conditions?

  1. Parotid gland
  2. Submandibular gland Correct answer.
  3. Minor palatal glands
  4. Sublingual gland

Explanation

At rest the submandibular glands contribute roughly two-thirds of salivary volume, while the parotid dominates only during stimulated flow. Minor glands contribute a very small fraction.

Question 4Oral Anatomy, Histology, and Physiology

The predominant mineral component of dental enamel is which compound?

  1. Calcium carbonate
  2. Magnesium phosphate
  3. Hydroxyapatite Correct answer.
  4. Fluorapatite

Explanation

Enamel is roughly 96% inorganic by weight, and that mineral is mainly hydroxyapatite, a crystalline calcium phosphate. Fluorapatite forms only in small amounts after fluoride exposure.

Question 5Oral Anatomy, Histology, and Physiology

Which cranial nerve provides general sensation to the anterior two-thirds of the tongue?

  1. Hypoglossal nerve
  2. Lingual branch of the trigeminal nerve Correct answer.
  3. Glossopharyngeal nerve
  4. Facial nerve

Explanation

General sensation from the anterior two-thirds of the tongue travels via the lingual nerve, a branch of the mandibular division of the trigeminal nerve. Taste from the same region is carried by the facial nerve.

Question 6Oral Anatomy, Histology, and Physiology

Which type of epithelium lines the attached gingiva?

  1. Parakeratinized simple columnar
  2. Pseudostratified ciliated columnar
  3. Keratinized stratified squamous Correct answer.
  4. Non-keratinized stratified squamous

Explanation

The masticatory mucosa of the attached gingiva is covered by a keratinized or parakeratinized stratified squamous epithelium suited to friction. Its keratinization is a functional adaptation to chewing forces.

Question 7Oral Anatomy, Histology, and Physiology

A patient's tooth shows a small, well-defined area of reduced enamel thickness with a sharp border where the enamel is thinner than normal. Which developmental disturbance does this describe?

  1. Dentinogenesis imperfecta
  2. Amelogenesis imperfecta of hypomaturation type
  3. Attrition
  4. Enamel hypoplasia Correct answer.

Explanation

Enamel hypoplasia is a quantitative defect producing pits, grooves, or localized thinning of enamel with a distinct border. It results from disruption of ameloblasts during matrix formation.

Question 8Oral Anatomy, Histology, and Physiology

During root development, the epithelial root sheath of Hertwig determines which feature?

  1. Pulp chamber volume
  2. Enamel thickness
  3. Number, size, and shape of roots Correct answer.
  4. Crown shape and cusp number

Explanation

Hertwig's epithelial root sheath grows apically between the dental papilla and follicle, guiding the number, size, and shape of the developing roots. It also induces odontoblast differentiation for root dentin.

Question 9Oral Anatomy, Histology, and Physiology

Which periodontal ligament fiber group is the principal resistance to intrusive forces on a tooth?

  1. Alveolar crest fibers
  2. Oblique fibers Correct answer.
  3. Apical fibers
  4. Horizontal fibers

Explanation

Oblique fibers run from bone apically to cementum coronally, so they resist intrusive and vertical loading by converting it to tension. They are the most numerous fiber group.

Question 10Oral Anatomy, Histology, and Physiology

A tooth demonstrates a developmental line in enamel that separates prenatally and postnatally formed enamel. This structure is known as which of the following?

  1. Hunter-Schreger band
  2. Line of Retzius
  3. Tomes process
  4. Neonatal line Correct answer.

Explanation

The neonatal line is an accentuated incremental line marking the abrupt change in enamel formation at birth. It separates prenatal from postnatal enamel and is prominent in deciduous teeth.

Question 11Oral Anatomy, Histology, and Physiology

Which cells are responsible for resorbing bone during orthodontic tooth movement?

  1. Cementoblasts
  2. Osteocytes
  3. Osteoclasts Correct answer.
  4. Osteoblasts

Explanation

Osteoclasts, derived from the monocyte-macrophage lineage, resorb bone on the pressure side of a moving tooth. Their activity allows the tooth to translate through the alveolar bone.

Question 12Oral Anatomy, Histology, and Physiology

Which primary dentin is formed before the completion of the apical foramen and constitutes the bulk of the dentin?

  1. Primary dentin Correct answer.
  2. Sclerotic dentin
  3. Tertiary dentin
  4. Secondary dentin

Explanation

Primary dentin is laid down before root completion and forms the main body of the tooth, including mantle and circumpulpal dentin. It is deposited at a relatively rapid, regular rate.

Question 13Oral Anatomy, Histology, and Physiology

The main excitatory neurotransmitter released at the neuromuscular junction of the masticatory muscles is which of the following?

  1. Gamma-aminobutyric acid
  2. Acetylcholine Correct answer.
  3. Dopamine
  4. Norepinephrine

Explanation

Motor neurons release acetylcholine at the neuromuscular junction, which binds nicotinic receptors on the muscle membrane to trigger contraction. Cholinesterase then terminates the signal.

Question 14Oral Anatomy, Histology, and Physiology

Which muscle of mastication is primarily responsible for protruding the mandible?

  1. Medial pterygoid
  2. Lateral pterygoid Correct answer.
  3. Masseter
  4. Temporalis

Explanation

The lateral pterygoid pulls the condyle and disc forward, producing protrusion and assisting in opening. It is the only masticatory muscle with a primarily protrusive action.

Question 15Oral Anatomy, Histology, and Physiology

A patient reports that sweet taste is perceived normally, but sour and bitter tastes are diminished. Which structure is most likely affected?

  1. Hypoglossal nerve
  2. Facial nerve chorda tympani fibers
  3. Glossopharyngeal nerve fibers from the posterior tongue Correct answer.
  4. Fungiform papillae on the anterior tongue

Explanation

The posterior third of the tongue, supplied by the glossopharyngeal nerve, is especially sensitive to bitter and sour. Loss of those modalities with preserved sweet taste points to the glossopharyngeal pathway.

Question 16Oral Anatomy, Histology, and Physiology

Which structure separates the oral cavity proper from the vestibule?

  1. The tongue
  2. The palate
  3. The alveolar ridges and teeth Correct answer.
  4. The uvula

Explanation

The alveolar ridges and their contained teeth form the boundary between the oral vestibule and the oral cavity proper. The vestibule lies between the lips and cheeks and the dental arches.

Question 17Oral Anatomy, Histology, and Physiology

Which tooth type typically has a root with a longitudinal groove on the mesial and distal surfaces and a single conical root?

  1. Maxillary first premolar
  2. Mandibular canine Correct answer.
  3. Mandibular first premolar
  4. Maxillary second molar

Explanation

The mandibular canine has a single, strong conical root that may show shallow longitudinal grooves on the mesial and distal aspects. Its robust root suits the heavy loading of this tooth.

Question 18Oral Anatomy, Histology, and Physiology

A 9-year-old child has a permanent maxillary central incisor with a chalky white opaque area and a surface that is soft and can be penetrated by a probe. Which type of amelogenesis imperfecta is most consistent with this finding?

  1. Hypomaturation type
  2. Fluorosis
  3. Hypoplastic type
  4. Hypocalcified type Correct answer.

Explanation

Hypocalcified amelogenesis imperfecta produces enamel of normal thickness that is soft, chalky, and easily lost because mineralization is defective. The marked softness and penetrability distinguish it from hypomaturation.

Question 19Oral Anatomy, Histology, and Physiology

A lesion destroys the cell bodies of the motor neurons supplying the tongue. Which functional deficit is most likely?

  1. Loss of sensation on the posterior tongue
  2. Deviation of the tongue toward the side of the lesion Correct answer.
  3. Loss of taste on the anterior tongue
  4. Reduced salivary flow from the parotid gland

Explanation

Hypoglossal motor neurons innervate the intrinsic and extrinsic tongue muscles; a unilateral lesion causes the tongue to deviate toward the weak side on protrusion. Taste and sensation travel by separate nerves.

Question 20Oral Anatomy, Histology, and Physiology

During normal mastication, which movement of the mandible is primarily produced by the coordinated action of the lateral pterygoid and the suprahyoid muscles?

  1. Depression and opening of the mandible Correct answer.
  2. Elevation of the mandible
  3. Lateral excursion to the ipsilateral side
  4. Retrusion of the mandible

Explanation

Mandibular opening results from lateral pterygoid activity pulling the condyle forward combined with suprahyoid muscle action lowering the mandible. The two groups act together to depress and protrude during opening.

Question 21Oral Pathology and Oral Medicine

Which organism is the principal causative agent of acute necrotizing ulcerative gingivitis (ANUG)?

  1. Streptococcus mutans
  2. Prevotella intermedia with spirochetes Correct answer.
  3. Herpes simplex virus type 1
  4. Candida albicans

Explanation

ANUG is a fusospirochetal infection in which a mixed anaerobic flora, classically Prevotella intermedia together with Treponema spirochetes, invades necrotic gingival tissue. Predisposing factors include stress, smoking, and poor oral hygiene. The other listed organisms cause caries, candidiasis, and herpetic lesions respectively.

Question 22Oral Pathology and Oral Medicine

A patient has a well-demarcated white plaque on the buccal mucosa that cannot be rubbed off and has no identifiable cause. What is the most appropriate clinical term for this lesion?

  1. Lichen planus
  2. Leukoplakia Correct answer.
  3. Frictional keratosis
  4. Candidiasis

Explanation

Leukoplakia is a clinical diagnosis reserved for a white patch that cannot be characterized as any other disease and cannot be rubbed off. By definition an identifiable cause such as friction or a known condition must be excluded first. It is a diagnosis of exclusion carrying malignant potential.

Question 23Oral Pathology and Oral Medicine

Which clinical feature most strongly suggests a diagnosis of oral squamous cell carcinoma?

  1. A soft fluctuant swelling that resolves spontaneously
  2. A painless ulcer with indurated, rolled margins persisting beyond two weeks Correct answer.
  3. A yellowish fluctuant nodule that empties on pressure
  4. Bilateral burning of the tongue relieved by antifungal therapy

Explanation

Squamous cell carcinoma typically presents as a persistent ulcer or mass with firm indurated edges that fails to heal within two weeks. Induration reflects tumor infiltration of underlying tissue. Any non-healing oral ulcer must therefore be biopsied.

Question 24Oral Pathology and Oral Medicine

Recurrent aphthous stomatitis of the minor type characteristically presents as:

  1. A single indurated ulcer on the lateral tongue
  2. Deep punched-out ulcers with attached gingival necrosis
  3. Vesicles that rupture to form coalescing erosions on the palate
  4. Multiple shallow round ulcers with a yellow floor and erythematous halo on non-keratinized mucosa Correct answer.

Explanation

Minor aphthous ulcers are shallow, round to oval, covered by a yellowish fibrin film with a red halo, and occur on non-keratinized mucosa such as the labial and buccal mucosa. They heal within about two weeks without scarring. Deeper or scarring ulcers suggest major aphthous or another diagnosis.

Question 25Oral Pathology and Oral Medicine

Which of the following is the most common odontogenic cyst of the jaws?

  1. Radicular cyst Correct answer.
  2. Lateral periodontal cyst
  3. Odontogenic keratocyst
  4. Dentigerous cyst

Explanation

The radicular (periapical) cyst is the most frequent odontogenic cyst and arises from inflammatory epithelial rests at the apex of a non-vital tooth. It is preceded by a periapical granuloma. Dentigerous and keratocysts are less common.

Question 26Oral Pathology and Oral Medicine

A painless, fluctuant, bluish swelling on the lower lip that fluctuates in size and often follows minor trauma is most likely:

  1. Fibroma
  2. Mucocele Correct answer.
  3. Pleomorphic adenoma
  4. Hemangioma

Explanation

A mucocele results from extravasation of saliva after trauma to a minor salivary gland duct, producing a bluish fluctuant swelling most often on the lower lip. It may rupture and refill. Hemangiomas blanch on pressure and are vascular.

Question 27Oral Pathology and Oral Medicine

Which vitamin deficiency is classically associated with angular cheilitis and a sore, beefy-red tongue?

  1. Vitamin C deficiency
  2. Vitamin K deficiency
  3. Vitamin B complex deficiency Correct answer.
  4. Vitamin D deficiency

Explanation

Deficiency of B-complex vitamins, particularly riboflavin, niacin, and B12, produces angular cheilitis, glossitis, and stomatitis. Vitamin C deficiency causes scurvy with bleeding gums, and vitamin D and K deficiencies do not typically cause these oral mucosal signs.

Question 28Oral Pathology and Oral Medicine

A 30-year-old reports recurrent episodes of unilateral facial palsy, facial edema, and fissured tongue. Which diagnosis best fits this combination?

  1. Sjögren syndrome
  2. Melkersson-Rosenthal syndrome Correct answer.
  3. Bell palsy
  4. Trigeminal neuralgia

Explanation

The triad of recurrent orofacial swelling, relapsing facial nerve palsy, and fissured (scrotal) tongue defines Melkersson-Rosenthal syndrome. When only granulomatous swelling is present it is termed cheilitis granulomatosa. Bell palsy is isolated and not associated with the other features.

Question 29Oral Pathology and Oral Medicine

A smoker presents with a white patch on the floor of the mouth that has a red, velvety area within it. What does the red component most likely indicate?

  1. Speckled leukoplakia with increased risk of dysplasia Correct answer.
  2. Recurrent herpes labialis
  3. Acute pseudomembranous candidiasis
  4. Simple frictional keratosis

Explanation

A white lesion containing red, atrophic areas is termed speckled leukoplakia, which carries a higher risk of epithelial dysplasia and malignant transformation than homogeneous leukoplakia. Biopsy is indicated. The red area represents loss of keratin with underlying inflammation or dysplasia.

Question 30Oral Pathology and Oral Medicine

Which radiographic feature best distinguishes an odontogenic keratocyst from other odontogenic cysts?

  1. A unilocular or multilocular radiolucency with a scalloped margin growing along the bone without causing expansion Correct answer.
  2. A radiolucency at the apex of a carious non-vital tooth
  3. A ground-glass radiopacity with cotton-wool appearance
  4. A well-defined radiolucency centered on the crown of an unerupted tooth

Explanation

The keratocyst tends to grow anteroposteriorly within medullary bone with minimal buccolingual expansion, producing a scalloped outline. This growth pattern and high recurrence rate are characteristic. The other options describe dentigerous cyst, radicular cyst, and fibrous dysplasia.

Question 31Oral Pathology and Oral Medicine

A patient on long-term inhaled corticosteroids develops removable white plaques on the palate that leave an erythematous base when wiped. What is the most likely diagnosis?

  1. Leukoplakia
  2. Geographic tongue
  3. Pseudomembranous candidiasis Correct answer.
  4. Lichen planus

Explanation

Inhaled corticosteroids suppress local immunity and predispose to Candida overgrowth, producing removable white pseudomembranes on an erythematous base. Confirmation is by smear or culture, and treatment is with topical antifungals plus rinsing after inhaler use.

Question 32Oral Pathology and Oral Medicine

Which feature most reliably differentiates a major aphthous ulcer from a minor aphthous ulcer?

  1. Location on the buccal mucosa
  2. Diameter greater than 1 cm with healing that may leave scarring Correct answer.
  3. Onset before puberty
  4. Presence of a yellow fibrin center

Explanation

Major aphthous ulcers exceed 1 cm, are deeper and more painful, persist for weeks, and may heal with scarring. Minor ulcers are under 1 cm and heal without scarring. Both share a fibrin-covered center and occur on non-keratinized mucosa.

Question 33Oral Pathology and Oral Medicine

A firm, sessile, pale pink nodule on the buccal mucosa at the line of occlusion in a patient who chews the cheek is best termed:

  1. Papilloma
  2. Lipoma
  3. Hemangioma
  4. Irritation fibroma Correct answer.

Explanation

An irritation fibroma is a reactive fibrous hyperplasia caused by chronic low-grade trauma such as cheek biting, presenting as a firm pale sessile nodule. It is composed of dense collagenous connective tissue. Removal of the irritant or simple excision is curative.

Question 34Oral Pathology and Oral Medicine

Which autoantibody is most characteristic of pemphigus vulgaris?

  1. IgA antibodies against epidermal transglutaminase
  2. Anti-SSA and anti-SSB antibodies
  3. IgG antibodies against basement membrane hemidesmosomes
  4. IgG antibodies against desmoglein 3 Correct answer.

Explanation

Pemphigus vulgaris is caused by IgG autoantibodies against desmoglein 3, producing intraepithelial acantholysis and suprabasal blisters. Direct immunofluorescence shows intercellular IgG in a net-like pattern. Antibasement membrane antibodies characterize bullous pemphigoid.

Question 35Oral Pathology and Oral Medicine

A patient with a history of a treated breast carcinoma develops a rapidly enlarging, painful swelling of the gingiva with loosening of adjacent teeth. What should be the primary concern?

  1. Periapical abscess
  2. Metastatic carcinoma to the gingiva Correct answer.
  3. Pericoronitis
  4. Pyogenic granuloma

Explanation

Metastatic tumors to the oral cavity often present as rapidly growing, painful swellings that may mimic inflammatory lesions and cause tooth mobility, with the gingiva being a common site. A known primary malignancy raises this suspicion. Biopsy is required for diagnosis.

Question 36Oral Pathology and Oral Medicine

Which condition is characterized by a triad of dry eyes, dry mouth, and bilateral parotid enlargement with an increased risk of lymphoma?

  1. Mikulicz disease
  2. Sialadenosis
  3. Sialolithiasis
  4. Sjögren syndrome Correct answer.

Explanation

Sjögren syndrome is an autoimmune exocrinopathy producing xerophthalmia and xerostomia, often with parotid enlargement. Patients carry a substantially increased risk of B-cell lymphoma, so persistent glandular enlargement warrants biopsy.

Question 37Oral Pathology and Oral Medicine

Which clinical presentation is most consistent with oral lichen planus?

  1. Multiple shallow ulcers on the floor of the mouth
  2. A single indurated ulcer with rolled edges
  3. A unilateral fixed white plaque on the lateral tongue
  4. Bilateral white reticular striae on the buccal mucosa with erosive areas Correct answer.

Explanation

Oral lichen planus typically produces bilateral, symmetric white striae (Wickham striae) on the buccal mucosa, sometimes with erosions. The bilateral symmetry and reticular pattern are key diagnostic features. Erosive forms require monitoring for malignant change.

Question 38Oral Pathology and Oral Medicine

A child with a history of recurrent epistaxis and multiple telangiectasias on the lips and tongue most likely has which condition?

  1. Immune thrombocytopenia
  2. Hereditary hemorrhagic telangiectasia Correct answer.
  3. Von Willebrand disease
  4. Hemophilia A

Explanation

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is an autosomal dominant disorder causing mucocutaneous telangiectasias and recurrent bleeding, often epistaxis. Oral lesions appear as small red-purple punctate vascular macules on the lips and tongue.

Question 39Oral Pathology and Oral Medicine

Which feature best distinguishes a ranula from a mucocele?

  1. A ranula contains keratinaceous debris and arises from the gingiva
  2. A ranula blanches on pressure and is present at birth
  3. A ranula is a firm fibrous nodule on the lower lip
  4. A ranula arises from the sublingual gland and presents as a large floor-of-mouth swelling Correct answer.

Explanation

A ranula is a mucocele arising from the sublingual gland or its duct, producing a translucent blue swelling in the floor of the mouth. Mucoceles typically arise from minor salivary glands of the lip. Both result from mucus extravasation.

Question 40Oral Pathology and Oral Medicine

A patient with poorly controlled diabetes develops a rapidly spreading, painful swelling of the floor of the mouth with elevation of the tongue and difficulty breathing. What is the immediate priority?

  1. Prescribing topical antifungal rinses
  2. Reassuring the patient and scheduling review in one week
  3. Performing an incisional biopsy of the swelling
  4. Securing the airway and urgent surgical drainage Correct answer.

Explanation

This presentation is consistent with Ludwig angina, a rapidly spreading cellulitis of the submandibular and sublingual spaces that can obstruct the airway. Immediate priority is airway protection, intravenous antibiotics, and surgical decompression. Delay is potentially fatal.

Question 41Oral Pathology and Oral Medicine

A biopsy of a white oral patch shows dysplastic epithelial cells confined above the basement membrane with intact basement membrane. What is the correct diagnosis?

  1. Epithelial dysplasia (carcinoma in situ) Correct answer.
  2. Invasive squamous cell carcinoma
  3. Verrucous carcinoma
  4. Hyperkeratosis without atypia

Explanation

Atypia limited to the epithelium with an intact basement membrane defines dysplasia; when the full thickness is involved it is termed carcinoma in situ. Invasion through the basement membrane would be required for a diagnosis of invasive carcinoma. Grading of dysplasia guides management.

Question 42Oral Pathology and Oral Medicine

A patient with a long-standing history of iron deficiency anemia, dysphagia, and a smooth atrophic tongue is suspected of having which syndrome?

  1. Gardner syndrome
  2. Plummer-Vinson syndrome Correct answer.
  3. Peutz-Jeghers syndrome
  4. Melkersson-Rosenthal syndrome

Explanation

Plummer-Vinson (Patterson-Kelly) syndrome comprises iron deficiency anemia, dysphagia from esophageal webs, and atrophic glossitis, and is associated with an increased risk of upper aerodigestive malignancy. The smooth tongue reflects loss of papillae.

Question 43Oral Pathology and Oral Medicine

Which histopathologic feature is characteristic of a pleomorphic adenoma?

  1. Onion-skin arrangement of lymphocytes around germinal centers
  2. A mixture of epithelial and myxochondroid stroma with a fibrous capsule Correct answer.
  3. Cords of odontogenic epithelium with calcifications
  4. Sheets of pleomorphic malignant cells with frequent mitoses

Explanation

Pleomorphic adenoma is a benign mixed tumor showing both epithelial and mesenchymal-like (myxochondroid) components within a capsule. The diverse stroma gives it its name. It is the most common salivary gland neoplasm and requires complete excision because of recurrence risk.

Question 44Oral Pathology and Oral Medicine

A 60-year-old with a non-healing, indurated ulcer of the lateral tongue has a biopsy showing invasive squamous cell carcinoma. Which factor most strongly predicts prognosis?

  1. Presence of a yellow fibrin floor
  2. History of aphthous ulcers
  3. Size of the ulcer alone
  4. Depth of invasion and presence of cervical lymph node metastasis Correct answer.

Explanation

In oral squamous cell carcinoma, the depth of tumor invasion and cervical nodal status are the strongest prognostic determinants, guiding staging and treatment. Nodal metastasis approximately halves survival. Clinical surface features are less predictive.

Question 45Operative Dentistry and Endodontics

Which instrument is used primarily to smooth and adapt the gingival margin of a Class II amalgam restoration?

  1. Hollenback carver Correct answer.
  2. Burnisher
  3. Discoid-cleoid carver
  4. Ardente plugger

Explanation

The Hollenback carver has a discoid blade used to carve and adapt the gingival and proximal contours of amalgam. A discoid-cleoid carver is used more for occlusal anatomy, and pluggers are for condensation rather than margin adaptation.

Question 46Operative Dentistry and Endodontics

What is the primary purpose of a rubber dam during endodontic treatment?

  1. To isolate the tooth and maintain a sterile field Correct answer.
  2. To stabilize the rubber dam clamp on adjacent teeth
  3. To improve access to the pulp chamber
  4. To reduce the need for local anesthesia

Explanation

The rubber dam isolates the operating field from oral fluids and prevents contamination of the root canal system. It also protects the patient from aspiration of instruments and irrigants, but isolation is its principal function.

Question 47Operative Dentistry and Endodontics

Which pulp diagnosis is characterized by a provoked, sharp pain of short duration that subsides when the stimulus is removed?

  1. Reversible pulpitis Correct answer.
  2. Necrosis
  3. Irreversible pulpitis
  4. Asymptomatic apical periodontitis

Explanation

Reversible pulpitis produces sharp, brief pain provoked by thermal or other stimuli that resolves after removal of the stimulus. Irreversible pulpitis typically produces spontaneous or lingering pain.

Question 48Operative Dentistry and Endodontics

In a Class I cavity preparation, what is the primary purpose of the cavosurface margin?

  1. To define the junction between prepared and unprepared tooth Correct answer.
  2. To provide retention for the restoration
  3. To determine the width of the isthmus
  4. To establish the pulpal floor depth

Explanation

The cavosurface margin is the junction where the prepared surface meets the unprepared tooth surface. Its design determines marginal seal and enamel rod orientation.

Question 49Operative Dentistry and Endodontics

What is the recommended working length for root canal preparation?

  1. 2 to 3 mm short of the radiographic apex
  2. At the radiographic apex
  3. 0.5 to 1 mm short of the radiographic apex Correct answer.
  4. At the apical foramen exactly

Explanation

Working length is conventionally established 0.5 to 1 mm short of the radiographic apex, which typically corresponds to the apical constriction. This minimizes damage to periapical tissues while ensuring the canal is cleaned.

Question 50Operative Dentistry and Endodontics

Which material is the most appropriate choice for a Class V restoration on a root surface with subgingival margins and poor moisture control?

  1. Microfilled composite
  2. Glass ionomer cement Correct answer.
  3. Amalgam
  4. Bonded ceramic

Explanation

Glass ionomer cements bond chemically to dentin, tolerate moisture reasonably well, and release fluoride, making them suitable for root-surface Class V lesions with difficult moisture control. Composite requires strict isolation for reliable bonding.