Ceramics 1

Question 1

Types of Ceramics

Answer 1

<p>Ceramic
Glasses
Glass-ceramics</p>

Question 2

Ceramic definition

Answer 2

<p>Refractory polycrystalline compound

| </p>

Question 3

Ceramic properties

Answer 3

<p>Usually inorganic
Highly inert
Hard and brittle
High compressive strength, low tensile
Generally good insulators
Good tribological props.
</p>

Question 4

Natural ceramic composites

Answer 4

<p>Bones, teeth, shells

| Hard tissues</p>

Question 5

Ceramic structures

Answer 5

<p>Crystalline
Semi-crystalline
Amorphous</p>

Question 6

Ceramic examples<

Answer 6

<p>Alumina
Bioglass
Ca Phosphates
Hydroxyapatite
Ca3 Phosphate</p>

Question 7

Bioactivity

Answer 7

<p>allows material to form a bond with living tissue

| stimulates healing by responding as if it were a natural tissue</p>

Question 8

Bioinert

Answer 8

<p>Not bonded
Relative movement (articulation)
Fibrous layer</p>

Question 9

Porous inert

Answer 9

<p>Tissue ingrowth
Fixation
Reduced movement</p>

Question 10

Surface reactive

Answer 10

<p>Chemical bonds
Slow degradation
Induces bone formation</p>

Question 11

Resorb-able

Answer 11

<p>Degrades</p>

Question 12

Ceramic processing

Answer 12

<p>Cast or Plasma spraying
Liquid-phase sintering
Solid-state sintering
Glass-ceramic
Glass</p>

Question 13

Ceramic Strengthening

Answer 13

For ceramics: to prevent fracture or inhibit crack propagation
They fracture easily under tension

Question 14

Polishing

Answer 14

Etch and Fire polish
Smaller grains
Eliminate flaws

Question 15

Annealing

Answer 15

eliminate residual stress

Question 16

Ion exchange

Answer 16

Intro of bigger cations within structure

Question 17

Porosity

Answer 17

3% porosity = 10x decrease in strength

Question 18

Alumina (Type 1)

Answer 18

Aluminum oxides
Nearly inert crystalline ceramic
Bioinert
Small grain and porosity = higher strength
Stress shielding problems
High hardness, low wear

Question 19

Alumina Applications

Answer 19

Orthopedics (heads, bone screws/plates

Dental crowns and bridges

Question 20

Type 2

Answer 20

Structural bridge or scaffold for bone formation

Question 21

Type 3

Answer 21

Bioactive glasses and glass-ceramics

Direct chemical bonding

Question 22

Glass (3)

Answer 22

inorganic melt cooled to solid w/o crystallization
Amorphous solid
Brittle

Question 23

Glass-ceramic

Answer 23

Polycrystalline solid

Stimulatory effect on bone

Question 24

Ca-Phosphate (3,4)

Answer 24

Naturally occurring (bone)
Poor mechanical behavior
Porosity determines: Tensile/Compressive strength and fatigue resistance

Question 25

Hydrolysis

Answer 25

degradation that increases with a decreasing Ca/P ratio

1. 0 = quick
2. 43 = 3-4 months

Question 26

Ca-P Apps.

Answer 26

Bone grafting
Non-major load bearing parts
Powders
Coatings
Bone fillers (temporary)

Question 27

Plasma Spraying Ca-P

Answer 27

most employed method for ceramic coating

Question 28

Resorbable Ca-P Biodegradation factors

Answer 28

Physiochemical dissolution
Physical disintegration
Biological factors

Question 29

Ca-P bone cements

Answer 29

Req. to be injectable and moldable

Drug delivery

Question 30

Hydroxyapatite (HA)

Answer 30

Bioactive and osteoconductive