Lecture 9 Flashcards
What is a biomaterial?
A biomaterial is any substance, other than a drug,
or combination of substances, synthetic or natural origin, which can be used for any period of time, as a whole or as a part of a system which treats, augments, or replaces* any tissue, organ, or function of the body
What is biocompatability?
The ability of a material to perform with an appropriate host response in a specific situation
What is the definition of ceramics?
Inorganic and non-metallic materials, mostly assembled through ionic bonding
What are some biomedical applications of ceramics?
Bone cements, dental applications, joint replacements, bone tissue engineering
True/ False: Ceramic properties such as cell interactions, mechanics, porosity, degradation/erosion depend on the application
True
Ceramics are primarily _____ in nature
ionic
What is crystal structure is influenced by?
- electric charge
- Size of cations and anions (want the charge to be neutral)
Describe the hardness and wear of ceramics.
high hardness and wear resistance
How do ceramics respond to compression?
Strong in compression; Fail catastrophically with little plastic deformation
How do we test mechanical properties?
apply stress and see how the material responds
Explain how ceramic fractures?
brittle fracture; formation and
propagation of cracks
perpendicular to applied load
What does the stress strain curve of ceramics look like
pretty steep slope and prettier linear
What are the three different ways you can create porous ceramic scaffolds?
replica, sacrificial, direct foaming, rapid prototyping
What is replica fabrication?
The use of a template that is later removed (think lattice)
What is sacrificial fabrication?
The use of a temporary place holder for pores. (think checkers)
What is direct foaming fabrication?
The use of gas bubbles to form pores
What is rapid prototyping fabrication?
3D object designed, scaffold built up layer by layer
What are the important parameters for ceramic fabrication?
pore structure, pore size, shape, distribution, connectivity
What properties are affected by porous ceramics?
mechanics, degradation, and cell invasion
What are some ways in which ceramics degrade?
Physiochemical dissolution, physical disintegration, and biological factors
What controls the rate of degradation of ceramic materials?
surface area and ceramic crystallinity
What is Physicochemical Dissolution?
solubility of the ceramic and local pH
What is physical disintegration?
mechanical disruption of
ceramic into particles
What is meant by biological factor degradation?
cellular uptake of ceramic particles (phagocytosis)
