281. The diameter of the largest arterial vessels in the pulp range from_____________?
A. 50-100 μm
B. 101-150 μm
C. 151-200 μm
D. 201-250 μm
✅ The correct answer is option A. 50-100 μm.
Oral Histology
282. Enamel spindles are formed by______________?
A. Cracks
B. Ameloblasts
C. Odontoblasts
D. Hypocalcified rods
✅ The correct answer is option C. Odontoblasts.
283. Neonatal lines are found in all of the following except____________?
A. Enamel of primary incisors
B. Enamel of permanent canines
C. Enamel and dentin of permanent first molars
D. Dentin of permanent mandibular incisors
✅ The correct answer is option B. Enamel of permanent canines.
284. Periodontal ligament has predominantly_________?
A. Type II collagen fibres
B. Oxytalan fibres
C. Elastic fibres
D. Type I collagen fibres
✅ The correct answer is option D. Type I collagen fibres.
285. Principal fibres of periodontal ligament are attached to_____________?
A. Alveolar bone proper
B. Bundle bone
C. Lamellar bone
D. Cortical bone
✅ The correct answer is option B. Bundle bone.
286. Reestablishing the former outline of the root surface is_____________?
A. Anatomic repair
B. Functional repair
C. Physiological repair
D. Hyperplasia
✅ The correct answer is option A. Anatomic repair.
287. Ionic exchange between enamel surface and environment______________?
A. Does not take place once enamel surface and invironment
B. Stops after 2 years of eruption
C. Continues till adult life
D. Continues through out life
✅ The correct answer is option D. Continues through out life.
288. The vascular supply of the periodontal ligament is______________?
A. Greatest in the middle-third of a single rotted tooth
B. Greatest in the middle-third of a multirooted tooth
C. A net like plexus that runs closer to the cementum than to the bone
D. A net like plexus that runs closer to the bone than to the cementum
✅ The correct answer is option D. A net like plexus that runs closer to the bone than to the cementum.
289. The cell free zone in pulp lies____________?
A. Above odontoblast
B. Below odontoblast
C. In radicular pulp
D. In pulp horn
✅ The correct answer is option B. Below odontoblast.
290. The maximum rate of eruption, as the tooth cusps reach the surface epithelium is around ________ μm/day?
A. 100
B. 75
C. 50
D. 25
✅ The correct answer is option B. 75.