MFDS Oral Biology 1 — Questions and Answers
Question 1: Which cells are responsible for forming dentine?
- Ameloblasts
- Odontoblasts (Correct answer)
- Cementoblasts
- Osteoblasts
Correct answer: Odontoblasts
Odontoblasts are the specialised cells derived from neural crest cells that synthesise and secrete the organic matrix of dentine.
Question 2: What is the predominant inorganic component of enamel?
- Calcium carbonate
- Hydroxyapatite (Correct answer)
- Fluorapatite
- Tricalcium phosphate
Correct answer: Hydroxyapatite
Hydroxyapatite [Ca10(PO4)6(OH)2] constitutes approximately 96% of the dry weight of mature enamel.
Question 3: Which type of collagen predominates in the pulp and dentine matrix?
- Type I (Correct answer)
- Type II
- Type III
- Type IV
Correct answer: Type I
Type I collagen is the major fibrillar collagen of dentine and pulp, providing tensile strength to the matrix.
Question 4: Hertwig's epithelial root sheath is derived from which structure?
- Dental follicle
- Enamel organ (Correct answer)
- Dental papilla
- Alveolar bone
Correct answer: Enamel organ
Hertwig's epithelial root sheath forms from the fusion of the inner and outer enamel epithelium at the cervical loop of the enamel organ.
Question 5: Which zone of the dental pulp is immediately deep to the odontoblast layer?
- Central zone
- Cell-rich zone
- Cell-free zone of Weil (Correct answer)
- Subodontoblastic plexus
Correct answer: Cell-free zone of Weil
The cell-free zone of Weil (also called the subodontoblastic zone) lies immediately beneath the odontoblast layer and is characterised by a relative absence of cell bodies.
Question 6: Perikymata are surface features found on which dental tissue?
- Cementum
- Dentine
- Enamel (Correct answer)
- Pulp
Correct answer: Enamel
Perikymata are the external manifestations of the striae of Retzius, appearing as transverse ridges on the enamel surface.
MFDS Oral Biology 1
Which cells are responsible for forming dentine?