Enamel MCQs

Option A: Each rod is formed by 4 ameloblasts

Option B: Each ameloblast contributes to 4 different rods

Option C: Head of the rod is formed by one ameloblasts, and tail is formed by three other ameloblasts

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Permeable membrane

Option B: Impermeable membrane

Option C: Semipermeable membrane

Option D: Infrapermeable membrane

Correct Answer: Semipermeable membrane ✔

Option A: Neonantal bands

Option B: Cross striations

Option C: Striae of Retzius

Option D: Hunter-Schregar bands

Correct Answer: Cross striations ✔

Option A: 10mm

Option B: 5mm

Option C: 2mm

Option D: 0.5mm

Correct Answer: 5mm ✔

Option A: Cracks

Option B: Pellicle

Option C: perikymata

Option D: Enamel lamellae

Correct Answer: perikymata ✔

Option A: Aprismatic enamel

Option B: Prismatic enamel

Option C: Intertubular dentin

Option D: Intratubular dentin

Correct Answer: Prismatic enamel ✔

Option A: Enamelin

Option B: Amelogenin

Option C: Tuftelin

Option D: Ameloplakin

Correct Answer: Amelogenin ✔

Option A: Organising

Option B: Formative/ Secretory

Option C: Protective

Option D: Desmolytic

Correct Answer: Formative/ Secretory ✔

Option A: Dental pulp

Option B: Odontoblastic processes

Option C: Dental sac

Option D: Reduced dental organ

Correct Answer: Dental sac ✔

Option A: Retzius line

Option B: Line of cross striations

Option C: Incremental lines

Option D: Line of enamel tufts

Correct Answer: Incremental lines ✔

Option A: Enamel lamella

Option B: Enamel rod

Option C: Enamel spindle

Option D: Enamel tuft

Correct Answer: Enamel rod ✔

Option A: Outer enamel epithelium

Option B: Ameloblast

Option C: Stratum intermedium

Option D: Stratum granulosum

Correct Answer: Ameloblast ✔

Option A: Mainly by odontoblasts

Option B: Mainly by ameloblasts

Option C: Only on odontoblasts

Option D: Only by ameloblasts

Correct Answer: Only by ameloblasts ✔

Option A: Presence of high percentage of organic matrix

Option B: Presence of incremental lines

Option C: Enamel has high reparative capacity

Option D: Most of organic component is lost during mineralization

Correct Answer: Most of organic component is lost during mineralization ✔

Option A: Morphogenic stage

Option B: Organizing stage

Option C: Desmolytic stage

Option D: Formative stage

Correct Answer: Organizing stage ✔

Option A: Hypoplasia of local origin

Option B: Hypoplasia of systemic origin

Option C: Hypoplasia of hereditary origin

Option D: None of the above

Correct Answer: Hypoplasia of systemic origin ✔

Option A: Non-scalloped

Option B: Straight

Option C: Scalloped and the convexities are directed towards dentin

Option D: Scalloped and the convexities are directed towards enamel

Correct Answer: Scalloped and the convexities are directed towards dentin ✔

Option A: They originate at right angle to dentin surface

Option B: They are almost vertical near the incisal edge (or) cusp tip areas

Option C: In the cervical third of deciduous crowns they are almost horizontal in direction

Option D: In cervical region of permanent teeth, they deviate in apical direction

Correct Answer: All of the above ✔

Option A: 4 μ m

Option B: 9 μ m

Option C: 7 μ m

Option D: 2 μ m

Correct Answer: 4 μ m ✔

Option A: 35%

Option B: 50%

Option C: 4%

Option D: 96%

Correct Answer: 96% ✔

Option A: Enamel matrix

Option B: Root

Option C: CEJ

Option D: DEJ

Correct Answer: DEJ ✔

Option A: It has only a small percent of organic content

Option B: Its formative cells are lost once it is completely formed

Option C: It is essentially a keratin tissue and has no blood vessels

Option D: It has no direct connection with the active cells of the dental pulp

Correct Answer: Its formative cells are lost once it is completely formed ✔

Option A: Enamel

Option B: Dentin

Option C: Periodontal ligament

Option D: Cementum

Correct Answer: Enamel ✔

Option A: Key hole appearance in cross section

Option B: Paddle appearance in cross section

Option C: Lanullate appearance in cross-section

Option D: None of the above

Correct Answer: Key hole appearance in cross section ✔

Option A: Constitute the rest lines with in the enamel rods

Option B: Have high inorganic content

Option C: They are areas of increased porosity

Option D: Allow the movement of water and small ions

Correct Answer: Have high inorganic content ✔

Option A: Does not take place once enamel surface and invironment

Option B: Stops after 2 years of eruption

Option C: Continues till adult life

Option D: Continues through out life

Correct Answer: Continues through out life ✔

Option A: Enamel

Option B: Dentin

Option C: Cementum

Option D: Pulp

Correct Answer: Enamel ✔

Option A: Tomes fibres

Option B: Tomes layer

Option C: Tomes processes

Option D: Odontoblastic processes

Correct Answer: Tomes fibres ✔

Option A: Enamel tufts

Option B: Enamel lamella

Option C: Incremental lines of enamel

Option D: Enamel cuticle

Correct Answer: Enamel tufts ✔

Option A: Dark and light bands of enamel seen in longitudinal ground section

Option B: Dark and light bands of enamel seen in horizontal ground section

Option C: Dark and light brands of dentin seen in longitudinal section

Option D: Dark and light bands of dentin seen in horizontal

Correct Answer: Dark and light bands of enamel seen in longitudinal ground section ✔

Option A: 66%

Option B: 76%

Option C: 86%

Option D: 96%

Correct Answer: 96% ✔

Option A: Tuftelin

Option B: Sheathlin

Option C: Enamelin

Option D: Amelogenin

Correct Answer: Amelogenin ✔

Option A: Same as dentin crystals

Option B: Contains organic portion in the center

Option C: Roughly texagonal in shape

Option D: Their diameter is about 5 microns in size

Correct Answer: Roughly texagonal in shape ✔

Option A: Bone

Option B: Enamel

Option C: Gingiva

Option D: Dentin

Correct Answer: Enamel ✔

Option A: Enamel of deciduous incisiors

Option B: Enamel of permanent incisors

Option C: Enamel of premolars

Option D: Dentin of all teeth, as if is formed first

Correct Answer: Enamel of deciduous incisiors ✔

Option A: Proximal surface of tooth

Option B: Cervical region of tooth

Option C: Cusp tips of tooth

Option D: All of the above

Correct Answer: Cusp tips of tooth ✔

Option A: 25 μ m

Option B: 50 μ m

Option C: 75 μ m

Option D: 100 μ m

Correct Answer: 25 μ m ✔

Option A: Straight

Option B: Shallow

Option C: Bent

Option D: Curved

Correct Answer: Bent ✔

Option A: As lines in the enamel running at right angles to the enamel surface

Option B: As lines in the dentin running at right angles to the dentino-enamel junction

Option C: In enamel and follow the apposition pattern

Option D: In dentin and follow the appositional pattern

Correct Answer: In enamel and follow the apposition pattern ✔

Option A: Cracks

Option B: Ameloblasts

Option C: Odontoblasts

Option D: Hypocalcified rods

Correct Answer: Odontoblasts ✔

Option A: Hyperplasia

Option B: Hypoplacification

Option C: Normal development

Option D: Interstitial development

Correct Answer: Normal development ✔

Option A: A cell from which tooth enamel is formed:

Option B: A tissue from which tooth erupts

Option C: A tumour of the jaw

Option D: Pertaining to dentin

Correct Answer: A cell from which tooth enamel is formed: ✔

Option A: Key hole or paddle shaped

Option B: Square

Option C: Round

Option D: None of the above

Correct Answer: Key hole or paddle shaped ✔

Option A: Odontodysplasia

Option B: Amelogenisis stage

Option C: Desmolytic stage

Option D: Mottled enamel

Correct Answer: Odontodysplasia ✔

Option A: Stratum inter medium

Option B: Stellate reticulum

Option C: Outer enamel epithelium

Option D: Cervical loop

Correct Answer: Cervical loop ✔

Option A: Enamel spindles

Option B: Enamel lamella

Option C: Enamel tufts

Option D: Perikymata

Correct Answer: Enamel lamella ✔

Option A: In cross sections enamel rods appear hexagonal and resembles fish scales

Option B: The bodies of rods are near occlusal and incisal surfaces, where as the tails point cervically

Option C: The apatite crystals are parallel to bodies and deviate 65° from the tails

Option D: All of the above

Correct Answer: All of the above ✔

Option A: Greater than the thickness of enamel

Option B: Less than the thickness of enamel

Option C: Equal to the thickness of enimal

Option D: None of the above

Correct Answer: Greater than the thickness of enamel ✔

Option A: 2.8

Option B: 3.8

Option C: 4.8

Option D: 2.3

Correct Answer: 2.8 ✔

Option A: Tono filament

Option B: Keratin like fibre

Option C: Collagen fibre

Option D: Vimentin filament

Correct Answer: Keratin like fibre ✔

Option A: Enamel

Option B: Dentin

Option C: Cementum

Option D: Periodontal ligament

Correct Answer: Enamel ✔

Option A: Hunter schreger bands

Option B: Enamel spindles

Option C: Enamel tufts

Option D: Enamel lamellae

Correct Answer: Enamel spindles ✔

Option A: Enamel of primary incisors

Option B: Enamel of permanent canines

Option C: Enamel and dentin of permanent first molars

Option D: Dentin of permanent mandibular incisors

Correct Answer: Enamel of permanent canines ✔

Option A: 5 million

Option B: 7 million

Option C: 9 million

Option D: 12 million

Correct Answer: 12 million ✔

Option A: Produced by ameloblasts

Option B: Found in the region of cusps

Option C: Surrounded by inter prismatic enamel

Option D: Terminate as rounded process

Correct Answer: Produced by ameloblasts ✔

Option A: Enamel spindles

Option B: Gnarled enamel

Option C: Incremental lies of woven

Option D: Incremental lines of retzius

Correct Answer: Gnarled enamel ✔

Option A: 1:4

Option B: 1:1

Option C: 1:2

Option D: 2:1

Correct Answer: 1:1 ✔

Option A: Thin tuft like structure extending from enamel surface of dentin enamel junction

Option B: Tuft like structure arising from dentin-enamel junction towards enamel surface

Option C: Odontoblastic processes extending into enamel

Option D: None of the above

Correct Answer: Tuft like structure arising from dentin-enamel junction towards enamel surface ✔

Option A: Cervical third of buccal surface

Option B: Middle third of buccal surface

Option C: Middle third of lingual surface

Option D: Occlusal surface

Correct Answer: Occlusal surface ✔

Option A: Enamel rods

Option B: Incremental lines of retzius

Option C: Nasmyth’s membrane

Option D: Pellicle

Correct Answer: Incremental lines of retzius ✔