Fundamentals of Dental Materials

Question 1

A narrow space around 3/4 of each rod giving enamel a keyhole shape. It makes the boundary between rod and interrod enamel.

Answer 1

Rod sheath

Question 2

Structural component of the hydroxyapatite-embedded collagen matrix

Answer 2

Intertubular dentin

Question 3

Composes the bulk of dentin

Answer 3

Intertubular dentin

Question 4

limited to the lining of the tubular walls and densely packed with apatite crystals

Answer 4

Peritubular dentin

Question 5

• What structure is in red?
• What strucutre is in blue?

Answer 5

• Red- Intertubular dentin
• Blue- Peritubular dentin

Question 6

What is the strongest and simplest molecular bond?

Answer 6

Covalent bonds

Question 7

What property of dental materials causes toxicity and sensitivity reactions that occur locally or systemically within associated tissues?

Answer 7

Biological

Question 8

Why will a low surface energy liquid readily spread over a high surface energy substrate?

Answer 8

Surface energy

Question 9

What is the measure of the affinity of a liquid for a solid as indicated by the spreading of a drop?

Answer 9

Wettability

Question 10

What are the two surface properties of materials

Answer 10

1. Surface energy
2. Wettability

Question 11

Adsorption

Answer 11

dissimilar substances in intimate contact with the surfaces of a solid (i.e. adherence)

Question 12

Will high or low energy surfaces adsorb molecules more readily?

Answer 12

High…. on a mountain top

Question 13

Absorption

Answer 13

The uptake of liquid by a bulk solid. The substance absorbed diffuses into the solid material.

Question 14

What happens when there is an uptake of liquid by a bulk solid?

Answer 14

Absorption

Question 15

What describes the action of dissimilar substances in intimate contact with surfaces of a solid?

Answer 15

Adsorption

Question 16

Which biocompatibility test is performed by placing a material in a situation indentical to its inteded clinical use? (i.e. in animals or humans)

Answer 16

Usage tests

Question 17

What happens when materials may not bond with sufficient strength to resist contraction on polymerization, wear, orthermal cycling?

Answer 17

Microleakage

Question 18

Microleakages can lead to

Answer 18

Gaps between tooth and restoration which allows influx of materials that may irritate the pulp.

Question 19

What pulpal reaction is caused by insufficiant bonding strength of materials which then influx to irritate the pulp?

Answer 19

Microleakage

Question 20

What is the most important protection of the pulp?

Answer 20

Remaining Dentinal Thickness (RDT)

Question 21

What is the minimum thickness of the RDT?

Answer 21

0.5mm