INBDE Oral Biology and Histology 1 — Questions and Answers
Question 1: Which cells are primarily responsible for producing dentin?
- Ameloblasts
- Odontoblasts (Correct answer)
- Cementoblasts
- Osteoblasts
Correct answer: Odontoblasts
Odontoblasts are the cells that synthesize and secrete the organic matrix of dentin throughout life.
Question 2: What is the primary inorganic component of enamel?
- Calcium carbonate
- Hydroxyapatite (Correct answer)
- Calcium fluoride
- Tricalcium phosphate
Correct answer: Hydroxyapatite
Hydroxyapatite crystals [Ca10(PO4)6(OH)2] make up approximately 96% of the inorganic content of mature enamel.
Question 3: Which structure connects the enamel organ to the oral epithelium during tooth development?
- Dental lamina (Correct answer)
- Stellate reticulum
- Stratum intermedium
- Outer enamel epithelium
Correct answer: Dental lamina
The dental lamina is the band of epithelium that connects the developing enamel organ to the oral epithelium.
Question 4: Hunter-Schreger bands in enamel are best described as:
- Incremental lines of enamel formation
- Alternating zones of enamel rods cut in different planes (Correct answer)
- Hypomineralized areas near the DEJ
- Cracks caused by acid etching
Correct answer: Alternating zones of enamel rods cut in different planes
Hunter-Schreger bands are optical phenomena produced by the alternating direction of enamel rods when viewed in reflected light.
Question 5: Which zone of the dental pulp contains the highest concentration of collagen fibers?
- Odontoblastic zone
- Cell-free zone of Weil
- Cell-rich zone
- Pulp core (Correct answer)
Correct answer: Pulp core
The pulp core (central zone) contains the largest blood vessels and nerves and has the highest density of collagen fibers.
Question 6: Cementum differs from bone primarily because cementum:
- Contains Haversian systems
- Is avascular (Correct answer)
- Is derived from the dental follicle
- Undergoes continuous remodeling
Correct answer: Is avascular
Cementum is avascular and receives its nutrition from the periodontal ligament, unlike bone which has its own blood supply via Haversian canals.
INBDE Oral Biology and Histology 1
Which cells are primarily responsible for producing dentin?