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SDLE (SPLE Dentist) study materials
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SDLE (SPLE Dentist) practice questions

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Question 1Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which tissue covers the crown of a tooth and is the most highly mineralized tissue in the human body?

  1. Cementum
  2. Enamel Correct answer.
  3. Pulp
  4. Dentin

Explanation

Enamel is formed by ameloblasts and is about 96% mineral by weight, making it the most highly mineralized tissue. Dentin and cementum are less mineralized, and pulp is soft connective tissue.

Question 2Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which muscle of mastication is chiefly responsible for depressing and protruding the mandible?

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

Explanation

The lateral pterygoid is the only muscle of mastication that opens the jaw; its inferior head protrudes the mandible and its superior head helps position the disc. The other three muscles are elevators of the mandible.

Question 3Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Taste sensation from the anterior two-thirds of the tongue is carried by which nerve?

  1. The chorda tympani branch of the facial nerve Correct answer.
  2. The vagus nerve
  3. The glossopharyngeal nerve
  4. The mandibular division of the trigeminal nerve

Explanation

Special taste fibres from the anterior tongue travel with the chorda tympani, a branch of the facial nerve, before joining the lingual nerve. General sensation from the same region is carried by the lingual branch of V3.

Question 4Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which ion shows the greatest proportional increase in parotid saliva as salivary flow rate rises from resting to maximal stimulation?

  1. Chloride
  2. Potassium
  3. Bicarbonate Correct answer.
  4. Sodium

Explanation

At high flow rates saliva spends less time in the striated ducts, so less bicarbonate is exchanged for chloride and the bicarbonate concentration rises steeply. Potassium concentration actually falls as flow increases.

Question 5Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Parathyroid hormone raises serum calcium by which combination of actions?

  1. Reducing osteoclast activity and bone turnover
  2. Decreasing intestinal calcium absorption
  3. Increasing renal phosphate reabsorption and calcitonin secretion
  4. Increasing renal calcium reabsorption and osteoclastic resorption Correct answer.

Explanation

PTH acts on the distal tubule to reclaim calcium and stimulates osteoblast signalling that recruits osteoclasts, releasing calcium from bone. It also increases calcitriol production, which raises intestinal calcium absorption.

Question 6Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

The resting membrane potential of a typical neuron lies closest to the equilibrium potential for which ion?

  1. Sodium
  2. Potassium Correct answer.
  3. Chloride
  4. Calcium

Explanation

At rest the membrane is far more permeable to potassium than to other ions, so the resting potential sits near the potassium equilibrium potential. Sodium permeability is low at rest and calcium permeability is negligible.

Question 7Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

What is the principal end product of anaerobic glycolysis in exercising skeletal muscle?

  1. Pyruvate
  2. Ethanol
  3. Lactate Correct answer.
  4. Acetyl-CoA

Explanation

When oxygen is limiting, lactate dehydrogenase converts pyruvate to lactate while regenerating NAD+, allowing glycolysis to continue. Ethanol formation occurs in yeast, not human muscle.

Question 8Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Vitamin C is required for which step in collagen synthesis?

  1. Hydroxylation of proline and lysine residues Correct answer.
  2. Formation of disulfide bonds
  3. Cleavage of the signal peptide
  4. Glycosylation of hydroxylysine

Explanation

Ascorbate is a cofactor for prolyl and lysyl hydroxylase, and hydroxylation stabilizes the collagen triple helix. Without it, underhydroxylated collagen is unstable and cannot be cross-linked properly.

Question 9Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which mechanism best explains the caries-preventive effect of topically applied fluoride?

  1. It chelates calcium and blocks dissolution
  2. It promotes formation of fluorapatite, which is less acid-soluble Correct answer.
  3. It raises salivary pH permanently
  4. It kills most plaque bacteria on contact

Explanation

Fluoride adsorbs to enamel and, during remineralization, is incorporated into the crystal lattice as fluorapatite, which dissolves at a lower pH than hydroxyapatite. Fluoride also inhibits bacterial enolase, but the dominant effect is reduced demineralization and enhanced remineralization.

Question 10Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which property of Streptococcus mutans is most important for its adherence to the tooth surface?

  1. Production of urease that raises plaque pH
  2. Formation of peritrichous flagella
  3. Production of glucosyltransferases that synthesize adherent glucans Correct answer.
  4. Secretion of collagenase that degrades dentin

Explanation

Glucosyltransferases convert sucrose into water-insoluble glucans that cement bacteria to the pellicle and to each other, forming cariogenic plaque. Urease actually buffers acids and is characteristic of organisms such as S. salivarius.

Question 11Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which organism is most strongly associated with chronic periodontitis and produces cysteine proteinases called gingipains?

  1. Streptococcus sanguinis
  2. Actinomyces viscosus
  3. Lactobacillus acidophilus
  4. Porphyromonas gingivalis Correct answer.

Explanation

Porphyromonas gingivalis is a black-pigmented anaerobe whose gingipains degrade collagen and immunoglobulins, driving tissue destruction in periodontitis. The other organisms listed are early plaque colonizers or cariogenic species.

Question 12Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which feature best distinguishes secretory IgA from serum IgA?

  1. It contains a J chain and a secretory component Correct answer.
  2. It activates complement through the classical pathway
  3. It crosses the placenta to reach the fetus
  4. It circulates mainly as a monomer

Explanation

Secretory IgA is a dimer of two IgA molecules joined by a J chain and wrapped by the secretory component, which protects it from proteolysis in mucosal secretions such as saliva. Serum IgA is mainly monomeric.

Question 13Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which cell is typically the first to arrive at the site of acute inflammation?

  1. Plasma cell
  2. Neutrophil Correct answer.
  3. Fibroblast
  4. Macrophage

Explanation

Neutrophils are recruited within minutes to hours by chemotactic signals such as IL-8 and complement C5a. Macrophages arrive later and predominate in chronic inflammation.

Question 14Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Granulation tissue in a healing wound consists mainly of which components?

  1. Fibrin and neutrophils only
  2. Mature bone and cartilage
  3. Dense collagen with very few capillaries
  4. Proliferating fibroblasts and newly formed capillaries Correct answer.

Explanation

Granulation tissue is the proliferative phase of repair, built from new capillaries (angiogenesis) and activated fibroblasts depositing loose extracellular matrix. It appears pink and granular clinically.

Question 15Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Full-thickness cytologic atypia of the oral epithelium with an intact basement membrane is diagnosed as which entity?

  1. Hyperkeratosis
  2. Invasive squamous cell carcinoma
  3. Carcinoma in situ Correct answer.
  4. Squamous metaplasia

Explanation

Carcinoma in situ shows dysplasia involving the entire epithelial thickness, but the basement membrane remains intact so there is no stromal invasion. Once atypical cells breach the basement membrane, the lesion is invasive carcinoma.

Question 16Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Local anesthetics produce nerve block by acting on which target?

  1. Opening potassium channels
  2. Stimulating inhibitory GABA receptors
  3. Blocking voltage-gated sodium channels Correct answer.
  4. Blocking voltage-gated calcium channels

Explanation

Local anesthetics bind the inner pore of voltage-gated sodium channels in the axon membrane, preventing the sodium influx needed for depolarization. Unmyelinated and small fibres are blocked first.

Question 17Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Aspirin produces its anti-inflammatory and analgesic effects chiefly by which action?

  1. Inhibiting phospholipase A2
  2. Blocking histamine H1 receptors
  3. Competitively blocking opioid receptors
  4. Irreversibly acetylating cyclooxygenase Correct answer.

Explanation

Aspirin acetylates a serine residue in cyclooxygenase-1 and -2, permanently inactivating the enzyme, so prostaglandin synthesis in platelets is lost until new platelets form. Other NSAIDs inhibit cyclooxygenase reversibly.

Question 18Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which cardiac condition is an accepted indication for antibiotic prophylaxis before invasive dental procedures?

  1. Mitral valve prolapse without regurgitation
  2. A permanent pacemaker
  3. A prosthetic heart valve Correct answer.
  4. Previous coronary artery bypass grafting

Explanation

Current guidelines recommend prophylaxis for patients with prosthetic valves, previous infective endocarditis, certain unrepaired or recently repaired congenital defects, and valvulopathy after cardiac transplantation. Coronary artery disease, pacemakers and uncomplicated prolapse are not indications.

Question 19Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Why is a vasoconstrictor such as epinephrine added to lidocaine cartridges?

  1. It increases the lipid solubility of lidocaine
  2. It shortens the duration of anesthesia
  3. It neutralizes the acidic cartridge solution
  4. It reduces blood flow at the injection site Correct answer.

Explanation

Vasoconstriction slows systemic absorption of the anesthetic, which prolongs the block, deepens anesthesia and lowers the risk of systemic toxicity. It also improves haemostasis in the surgical field.

Question 20Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

The articular disc of the temporomandibular joint is composed primarily of which tissue?

  1. Fibrocartilage Correct answer.
  2. Elastic cartilage
  3. Hyaline cartilage
  4. Cancellous bone

Explanation

The TMJ disc is dense fibrocartilage with few chondrocytes, which allows it to withstand compressive and shear forces. Hyaline cartilage covers the articular surfaces of most other synovial joints.

Question 21Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Osteoclasts arise from which source?

  1. Osteoblast precursors
  2. Chondroblast precursors
  3. The monocyte–macrophage lineage Correct answer.
  4. Mesenchymal stromal cells

Explanation

Osteoclasts are multinucleated cells formed by fusion of haematopoietic precursors of the monocyte–macrophage lineage. Osteoblasts, by contrast, derive from mesenchymal osteoprogenitor cells.

Question 22Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which buffer system provides the greatest buffering capacity in extracellular fluid?

  1. Intracellular protein buffer
  2. Phosphate buffer
  3. Haemoglobin
  4. Bicarbonate–carbonic acid system Correct answer.

Explanation

The bicarbonate–carbonic acid system is the principal extracellular buffer, and its effectiveness depends on respiratory control of CO2 and renal regulation of bicarbonate. Haemoglobin and protein buffers act mainly inside cells.

Question 23Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Steam autoclaving at 121 °C and 15 psi sterilizes dental instruments by which action?

  1. Denaturing proteins at 121 °C under pressure Correct answer.
  2. Retaining spores on a 0.22 µm filter
  3. Cross-linking DNA with ultraviolet light
  4. Oxidizing lipids at 160 °C in dry heat

Explanation

Pressurized saturated steam at 121 °C for about 15 minutes coagulates and denatures microbial proteins, including bacterial spores. Dry heat and chemical sterilants act by oxidation and alkylation respectively.

Question 24Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which clinical finding most suggests irreversible pulpitis rather than reversible pulpitis?

  1. A normal response to electric pulp testing
  2. Pain only on percussion of the tooth
  3. Lingering pain after the thermal stimulus is removed Correct answer.
  4. Sharp pain on cold lasting a few seconds

Explanation

In irreversible pulpitis the pain persists for minutes to hours after the stimulus is removed, often occurring spontaneously at night. Reversible pulpitis produces sharp, brief pain that resolves immediately once the stimulus stops.

Question 25Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Acute fluoride toxicity after accidental ingestion of a high dose is dominated by which effect?

  1. Hypocalcaemia leading to cardiac arrhythmias Correct answer.
  2. Hepatic necrosis from free radicals
  3. Calcium oxalate kidney stones
  4. Demyelination of the optic nerve

Explanation

Fluoride binds avidly to calcium, causing hypocalcaemia and secondary hyperkalaemia that can provoke ventricular arrhythmias and tetany. Treatment therefore focuses on calcium replacement and cardiac monitoring.

Question 26Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which nerve provides motor innervation to the muscles of mastication?

  1. Facial nerve, which supplies muscles of facial expression
  2. Mandibular division of the trigeminal nerve Correct answer.
  3. Hypoglossal nerve, which supplies the tongue
  4. Glossopharyngeal nerve, which supplies the pharynx

Explanation

The mandibular division of the trigeminal nerve (V3) carries motor fibers to the masseter, temporalis, medial pterygoid, and lateral pterygoid, as well as the mylohyoid and anterior digastric. The facial nerve supplies muscles of facial expression, while the hypoglossal and glossopharyngeal nerves supply the tongue and pharynx, respectively.

Question 27Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which hormone acts on bone and kidney to raise the serum calcium concentration?

  1. Calcitonin, which lowers serum calcium
  2. Parathyroid hormone, which increases bone resorption Correct answer.
  3. Insulin, which promotes cellular glucose uptake
  4. Aldosterone, which increases renal sodium reabsorption

Explanation

Parathyroid hormone raises serum calcium by increasing renal calcium reabsorption, activating vitamin D, and stimulating osteoclastic bone resorption indirectly through osteoblast signaling. Calcitonin has the opposite effect and lowers serum calcium.

Question 28Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which enzyme catalyzes the committed rate-limiting step of glycolysis?

  1. Pyruvate kinase
  2. Lactate dehydrogenase
  3. Hexokinase
  4. Phosphofructokinase-1 Correct answer.

Explanation

Phosphofructokinase-1 converts fructose-6-phosphate to fructose-1,6-bisphosphate and is the committed, rate-limiting step of glycolysis. It is allosterically inhibited by ATP and citrate and activated by AMP and fructose-2,6-bisphosphate.

Question 29Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

Which virulence factor produced by Aggregatibacter actinomycetemcomitans kills neutrophils and contributes to aggressive periodontitis?

  1. Leukotoxin Correct answer.
  2. Streptolysin O
  3. M protein
  4. Panton-Valentine leukocidin

Explanation

Aggregatibacter actinomycetemcomitans produces leukotoxin (LtxA), which forms pores in host leukocytes and impairs neutrophil function, a key feature of aggressive periodontitis. The organism also produces cytolethal distending toxin and lipopolysaccharide.

Question 30Basic Biomedical Sciences (Anatomy, Physiology, Biochemistry, Microbiology, Pathology, Pharmacology)

A patient stabilized on warfarin is prescribed metronidazole. Which interaction is most likely?

  1. Increased warfarin effect through CYP2C9 inhibition Correct answer.
  2. No interaction because metronidazole is not protein bound
  3. Increased warfarin effect through enhanced platelet aggregation
  4. Reduced warfarin effect through enzyme induction

Explanation

Metronidazole inhibits CYP2C9, reducing the metabolism of S-warfarin and thereby increasing its anticoagulant effect and INR. Patients on warfarin should have INR monitored closely when metronidazole is started.

Question 31Dental Anatomy, Oral Histology and Oral Physiology

Which permanent tooth is usually the first to erupt into the oral cavity?

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

Explanation

The permanent dentition usually begins with the first molars at about 6 years of age, which is why they are commonly called the six-year molars. The mandibular first molar generally emerges slightly ahead of the maxillary first molar and before the incisors are shed and replaced.

Question 32Dental Anatomy, Oral Histology and Oral Physiology

Approximately what proportion of mature enamel, by weight, is inorganic material?

  1. 96% Correct answer.
  2. 70%
  3. 85%
  4. 50%

Explanation

Mature enamel is the most highly mineralized tissue in the body, consisting of about 96% inorganic material by weight, chiefly hydroxyapatite. Only a small fraction is water and organic matrix, which is why enamel cannot regenerate once lost.

Question 33Dental Anatomy, Oral Histology and Oral Physiology

How many roots does a maxillary first molar typically possess?

  1. Two
  2. One
  3. Four
  4. Three Correct answer.

Explanation

The maxillary first molar normally has three roots: mesiobuccal, distobuccal and a large palatal root. It also typically shows three or four canals, with the mesiobuccal root often containing two.

Question 34Dental Anatomy, Oral Histology and Oral Physiology

The first layer of dentin deposited, lying immediately beneath the enamel, is termed:

  1. Circumpulpal dentin
  2. Secondary dentin
  3. Reparative dentin
  4. Mantle dentin Correct answer.

Explanation

Mantle dentin is the initial layer laid down by the newly differentiated odontoblasts, and it is the outermost dentin next to the dentinoenamel junction. The bulk of the primary dentin formed afterwards is the circumpulpal dentin.

Question 35Dental Anatomy, Oral Histology and Oral Physiology

Enamel demineralization begins when plaque fluid pH falls below approximately:

  1. 5.5 Correct answer.
  2. 7.0
  3. 4.5
  4. 6.5

Explanation

The critical pH for enamel is about 5.5, the point at which the aqueous phase of plaque becomes unsaturated with respect to hydroxyapatite. Below this value, mineral dissolves from the tooth surface faster than it can be redeposited.

Question 36Dental Anatomy, Oral Histology and Oral Physiology

In permanent teeth, the most frequent relationship found at the cementoenamel junction is:

  1. An edge-to-edge meeting of cementum and enamel
  2. Enamel overlapping the cervical cementum
  3. Cementum overlapping the cervical enamel Correct answer.
  4. A gap exposing the underlying root dentin

Explanation

In permanent teeth cementum most often overlaps the cervical enamel, followed by an edge-to-edge apposition. A true gap with exposed dentin is the least common arrangement and is seen more frequently in deciduous teeth.

Question 37Dental Anatomy, Oral Histology and Oral Physiology

The organic matrix of developing enamel is dominated by proteins of which family?

  1. Osteocalcin
  2. Amelogenins Correct answer.
  3. Type I collagen
  4. Fibronectin

Explanation

Amelogenins make up the great majority of the developing enamel matrix and are thought to regulate crystal growth and spacing. They are largely degraded and removed during maturation of the tissue.

Question 38Dental Anatomy, Oral Histology and Oral Physiology

Which principal periodontal ligament fibre group is chiefly responsible for resisting axially directed forces?

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

Explanation

Oblique fibres run from cementum apically and distally to the alveolar bone, converting axial occlusal load into tension on the ligament. They are the most numerous group and the principal load-bearing element.

Question 39Dental Anatomy, Oral Histology and Oral Physiology

The dental lamina arises from which embryonic germ layer?

  1. Mesoderm
  2. Endoderm
  3. Ectoderm Correct answer.
  4. Ectomesenchyme

Explanation

The dental lamina is a band of epithelium derived from the oral ectoderm that invaginates into the underlying mesenchyme. The ectomesenchyme derived from neural crest subsequently condenses to form the dental papilla and follicle.

Question 40Dental Anatomy, Oral Histology and Oral Physiology

Which lingual papillae are the most numerous and bear no taste buds?

  1. Filiform Correct answer.
  2. Foliate
  3. Fungiform
  4. Circumvallate

Explanation

Filiform papillae are the smallest and most numerous papillae on the tongue and are covered by keratinized epithelium for mechanical function. They carry no taste buds; taste buds reside in fungiform, circumvallate and foliate papillae.

Question 41Dental Anatomy, Oral Histology and Oral Physiology

Attachment of the junctional epithelium to the tooth surface is achieved mainly through:

  1. Tight junctions
  2. Hemidesmosomes Correct answer.
  3. Gap junctions
  4. Desmosomes

Explanation

The junctional epithelium attaches to the enamel or cementum by hemidesmosomes linked to an internal basal lamina. This epithelial attachment, together with the gingival seal, forms the main barrier against bacterial invasion.

Question 42Dental Anatomy, Oral Histology and Oral Physiology

Gnarled enamel is characteristically found:

  1. Along the dentinoenamel junction of the root
  2. Beneath the cusps and incisal edges Correct answer.
  3. In the floor of occlusal fissures
  4. At the cervical margin of the crown

Explanation

Beneath cusps and incisal edges the enamel rods interweave in a complex pattern rather than following a straight path, producing the appearance known as gnarled enamel. This arrangement adds strength in regions of heavy occlusal stress.

Question 43Dental Anatomy, Oral Histology and Oral Physiology

The articular disc of the temporomandibular joint is composed of:

  1. Fibrocartilage Correct answer.
  2. Compact bone
  3. Elastic cartilage
  4. Hyaline cartilage

Explanation

The temporomandibular disc is a biconcave sheet of dense fibrocartilage with few cells and abundant collagen fibres. This composition allows it to withstand compressive and shear loads during jaw movement.

Question 44Dental Anatomy, Oral Histology and Oral Physiology

Hunter-Schreger bands observed in ground sections of enamel represent:

  1. Incremental lines of growth
  2. Artefacts produced by decalcification
  3. Alternating changes in rod direction Correct answer.
  4. Zones of hypomineralized enamel

Explanation

Hunter-Schreger bands are optical phenomena caused by alternating layers of enamel rods whose direction changes relative to the plane of section. They reflect the decussating arrangement of rods that strengthens the tissue.

Question 45Dental Anatomy, Oral Histology and Oral Physiology

The S-shaped curvature of dentinal tubules is most pronounced in:

  1. The incisal edge
  2. Coronal dentin Correct answer.
  3. The apical third
  4. Root dentin

Explanation

Tubules pursue a primary S-shaped curve from the pulp to the dentinoenamel junction, and this curvature is most marked in coronal dentin. In root dentin the tubules are fewer and run a straighter course.

Question 46Dental Anatomy, Oral Histology and Oral Physiology

The principal buffer system responsible for the buffering capacity of saliva is:

  1. Protein
  2. Bicarbonate Correct answer.
  3. Amylase
  4. Phosphate

Explanation

Bicarbonate is the dominant buffer in stimulated saliva and accounts for most of its capacity to neutralize dietary and bacterial acids. Its concentration rises with salivary flow rate, increasing buffering during chewing.

Question 47Dental Anatomy, Oral Histology and Oral Physiology

In FDI two-digit notation, tooth 36 designates the:

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

Explanation

In FDI notation the first digit indicates the quadrant and the second the tooth position. Quadrant 3 is the mandibular left, and position 6 is the first molar, so 36 is the mandibular left first molar.

Question 48Dental Anatomy, Oral Histology and Oral Physiology

Histologically, the dental pulp is best classified as:

  1. Hyaline cartilage
  2. Adipose tissue
  3. Dense regular connective tissue
  4. Loose connective tissue Correct answer.

Explanation

The pulp is a soft, loose connective tissue with abundant ground substance, scattered fibroblasts and a rich vascular and nerve supply. Its gelatinous matrix allows exchange of nutrients with the odontoblast layer despite the rigid surrounding dentin.

Question 49Dental Anatomy, Oral Histology and Oral Physiology

Masticatory forces are greatest in which region of the dental arch?

  1. Incisal region
  2. Molar region Correct answer.
  3. Premolar region
  4. Canine region

Explanation

Force magnitude increases progressively along the arch from incisors to molars because of the larger periodontal surface area and proximity to the muscles of mastication. The molar region therefore generates the highest biting and chewing loads.

Question 50Dental Anatomy, Oral Histology and Oral Physiology

Acellular cementum is found predominantly in the:

  1. Apical third of the root
  2. Middle third of the root
  3. Furcation area
  4. Cervical third of the root Correct answer.

Explanation

Acellular, or primary, cementum forms first and covers approximately the cervical third of the root, where it is thin and contains no embedded cementocytes. Cellular cementum is deposited later and predominates apically and in the furcation.