ID6 Tooth histology Practical

Question 1

Why can enamel not be identified on a section that has been decalcified section, stained with silver nitrate?

Answer 1

In decalcified tooth sections, all mineralised tissue has been removed as part of the tissue processing protocol. This is necessary for preparation of thin sections (4-10 um). Because enamel is highly mineralised, it is completely removed during tissue processing whereas the protein components of dentine (~30%) remain and can be visualised using histological stains.

Question 2

Nerve endings are present between the odontoblasts (~0.3-0.5 microns). What is the function of these nerve endings?

Answer 2

dentine-pulp complex is able to sense changes in the dentine such as tooth wear or progressing caries. There are three different theories how the nerves in the dental pulp could be involved in this process.

Question 3

What are the different structures present in the dental pulp?

Answer 3

a) fibrous connective tissue (collagen)
b) blood vessels
c) cell rich zone
d) cell free zone
4) nerves
f) odontoblast cells

Question 4

Why does the neonatal line form? Which teeth can it be found in?

Answer 4

The neonatal line is an exaggerated incremental growth line that has formed in response to physiological stress caused by birth. It is only present in primary teeth and first permanent molars.

Question 5

What are 2 visual differences between primary molars and permanent molar:

Answer 5

Enamel thickness: Primary teeth have thinner enamel than permanent teeth.

Scalloping at the enamel-dentine junction (EDJ): Primary teeth form faster and therefore show less scalloping at the EDJ.

Question 6

Name three major functions of teeth.

Answer 6

Mechanical break-down of food: cutting, tearing, crushing, grinding  First step in digestion of food Involved in speech (e.g. production of ‘f’ and ‘ch’ sounds) Giving confidence (Tooth aesthetics)

Question 7

What are the cells that form enamel called?

Answer 7

Once enamel is destroyed, can it be replaced or regenerated? Ameloblasts

Question 8

What is the process of enamel formation called?

Answer 8

Amelogenesis

Question 9

Once enamel is destroyed, can it be replaced or regenerated?

Answer 9

duce dentineNo, because ameloblasts cannot regenerate and are lost as the tooth erupts into oral cavity.

Question 10

What is the main organic component of dentine?

Answer 10

Collagen fibres (mainly type 1)

Question 11

What cells produce dentine?

Answer 11

odontoblasts

Question 12

Why is the enamel-dentine junction scalloped (wavy)?

Answer 12

To provide a greater surface area for tight interlocking of enamel and dentine.

Question 13

What does the term odontogenesis mean?

Answer 13

Formation and development of teeth

Question 14

question 9

Answer 14

q