Biomaterials

Question 1

What is the definition of a biomaterial?

Answer 1

natural or synthetic material that is used to supplement or replace the functions of living tissues

Question 2

List the 2 types of implants, and give examples.

Answer 2

1) transient implants- Ex. sutures, dressings, fixation devices
2) permanent implants- heart valves, joint replacement devices

Question 3

What is biocompatibility?

Answer 3

considers the host’s response to a material and the physiological effect of the environment on the material

Question 4

What are 2 categories of biocompatibility that are essential to biomaterials?

Answer 4

1) biologic biocompatibility- host’s reaction to implant

2) mechanical biocompatibility-properties of the material and its intended function

Question 5

what is the most commonly used test of mechanical properties of a material?

Answer 5

tensile test- a material is stretched at a constant rate, while the force applied to the material and teh elongation of the material is measured

Question 6

what is the definition of stress?

Answer 6

ratio of applied force to cross-sectional area

Question 7

what is the definition of strain?

Answer 7

ratio of change in length to the original length of the material specimen

Question 8

a high modulus of elasticity indicates what about the material?

Answer 8

it is relatively stiff

Question 9

what is creep?

Answer 9

permanent deformation that occurs over time as a result of an applied constant stress. It is a manifestation of viscoelasticity.

Question 10

what are the 3 categories of materials used as biomaterials?

Answer 10

1. metals
2. polymers
3. ceramics

Question 11

what are the 3 metals most commonly used as biomaterials?

Answer 11

1. titanium
2. cobalt-chromium
3. stainless steel

Question 12

what type of hypersensitivity results in an allergic response?

Answer 12

type 4 hypersensitivity (delayed response; primarily cell-mediated)

Question 13

which metal is the most allergenic? why?

Answer 13

stainless steel (contains 13-15% nickel) and nickel sensitivity is the most common.

Question 14

what are some applications of absorbable polymers?

Answer 14

drug delivery systems
bone fillers
wound care products
tissue scaffolds
nerve guides