Metallic Implant Materials Flashcards Preview

Biomech/mat Exam 1 > Metallic Implant Materials > Flashcards

Flashcards in Metallic Implant Materials Deck (12)
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1

Requirements

Excellent biocompatibility
Corrosion resistance
Adequate strength and ductility
Adequate fatigue and wear resistance
Appropriate modulus
Formability

2

Why use

High elastic moduli
Reasonable yield points
High ductility
Plastic deformation
Withstands cyclic loading
Fabrication

3

Physical and chemical properties

Luster
Good conductors of heat and electricity
High melting point
Ductile
Malleable
Easily lose electrons
Surface reactive
Loss of mass
Change in mechanical properties

4

Cobalt-chromium (CoCr) alloys

30-60% cobalt
20-30% chromium
Corrosion resistant
Good biocompatibility
Wear resistant
Long service life
Fracture and fatigue resistant

5

Gold and platinum

Used in dental fillings
Electrodes for cochlear implants

6

Silver tin copper alloys

Used in dental amalgams

7

Stainless steel

Temporary implant devices
Corrosion resistant
Best:
302, 316, 316L, 316L VM

8

Titanium alloys

Compared to cobalt chrome and stainless steel:
Lower elastic mod
Lower density
Fatigue resistant
Corrosion resistant
Osseointegration tendencies
Poor wear(low shear strength)
Does not machine well

9

Nickel titanium alloys

Shape memory effect(Ni-Ti)
Low elastic moduli
Resilient

10

Tantalum

Very biocompatible
High density
80% porous
High coefficient of friction

11

Trabecular metal

High strength to weight ratio
Compressive strength and elastic mod more similar to bone
Low stiffness facilitates physiologic load transfer

12

Stress shielding

Lack of stress decreases bone mass