Stainless Steel and Titanium Alloys in Biomaterials: Properties and Applications

Question 1

Which ethical principle is essential for medical device clinical trials?

Accepted Answer

Ethical approval from relevant committees

Answer

Animal testing before human involvement

Answer

No regulatory oversight of design and manufacturing

Answer

Informed consent from patients is not required

Question 2

Titanium alloys are renowned for their: [High specific strength, Limited corrosion resistance, Poor biocompatibility, Low ductility]

Accepted Answer

High specific strength

Answer

Limited corrosion resistance

Answer

Poor biocompatibility

Answer

Low ductility

Question 3

Which of the following factors does NOT influence the mechanical properties of titanium alloys? [Alloy composition, Heat treatment, Surface roughness, Grain size]

Accepted Answer

Surface roughness

Answer

Alloy composition

Answer

Heat treatment

Answer

Grain size

Question 4

What is the primary advantage of using titanium alloys in dental restorations?

Accepted Answer

Combination of all these factors, providing a comprehensive solution

Answer

Excellent resistance to wear and tear, increasing implant longevity

Answer

Aesthetically pleasing appearance, matching the natural color of teeth

Answer

Low toxicity, minimizing potential harm to surrounding tissues

Question 5

Which of the following factors most significantly affects the biocompatibility of a biomaterial?

Accepted Answer

Combination of all these factors, contributing to overall biocompatibility

Answer

Surface chemistry, influencing interactions with biological systems

Answer

Mechanical properties, determining load-bearing capacity and implant stability

Answer

Biological interactions, including cell adhesion, proliferation, and response

Question 6

What is the main limitation of using stainless steel in certain biomedical applications?

Accepted Answer

Potential release of metal ions into the body, raising concerns about long-term health effects

Answer

High cost of production, making it less cost-effective than alternative materials

Answer

Low strength compared to other materials, limiting its use in load-bearing applications

Answer

Brittle nature, increasing the risk of fracture under stress

Question 7

Which type of titanium alloy is widely used for orthopedic implants due to its exceptional strength and biocompatibility?

Accepted Answer

Ti-6Al-4V, offering a balance of strength, corrosion resistance, and biocompatibility

Answer

Ti-15Mo-5Zr-3Al, known for its high strength and wear resistance

Answer

Ti-13Nb-13Zr, valued for its excellent biocompatibility and corrosion resistance

Answer

Ti-3Al-2.5V, characterized by its low modulus of elasticity, making it suitable for load-bearing applications

Question 8

What is the role of passivation in enhancing the corrosion resistance of stainless steel?

Accepted Answer

Formation of a protective chromium oxide layer on the surface, preventing further corrosion

Answer

Addition of alloying elements, such as chromium and nickel, to improve electrochemical properties

Answer

Coating the material with a protective layer, such as a polymer or ceramic

Answer

Heat treatment to increase the hardness of the material, making it less susceptible to wear

Question 9

What is the primary reason for the use of titanium alloys in dental implants?

Accepted Answer

Combination of all these factors, making titanium alloys the preferred choice for dental implants

Answer

Exceptional strength and durability, ensuring long-term functionality under chewing forces

Answer

Inertness and biocompatibility, minimizing adverse reactions in the oral environment

Answer

Ability to integrate with bone tissue through osseointegration, providing stability

Question 10

Which of the following surface treatments can be used to improve the biocompatibility of titanium alloys?

Accepted Answer

Combination of all these treatments, providing a synergistic effect on biocompatibility

Answer

Anodization, creating a protective oxide layer and enhancing cell adhesion

Answer

Plasma nitriding, modifying the surface chemistry to improve wear resistance and biocompatibility

Answer

Hydrothermal treatment, altering the surface topography to promote cell growth

Question 11

Which primary alloying element contributes to the corrosion resistance of stainless steel used for orthopedic implants?

Accepted Answer

Chromium

Answer

Copper

Answer

Nickel

Answer

Zinc

Question 12

What dominant crystal structure is characteristic of titanium alloys employed in dental restorations?

Accepted Answer

Hexagonal close-packed (HCP)

Answer

Face-centered cubic (FCC)

Answer

Body-centered cubic (BCC)

Answer

Amorphous

Question 13

What term describes the release of metallic ions from an implant into surrounding tissues?

Accepted Answer

Metallosis

Answer

Wear

Answer

Corrosion

Answer

Osseointegration

Question 14

Which of the following is NOT a common type of stainless steel used in orthopedic implants?

Accepted Answer

Nitinol

Answer

316L

Answer

304

Answer

17-4PH

Question 15

What is the primary mechanism by which titanium alloys achieve biocompatibility?

Accepted Answer

Formation of a stable oxide layer

Answer

Inertness to biological fluids

Answer

Low modulus of elasticity

Answer

High electrochemical potential

Question 16

What is the primary disadvantage of titanium alloys compared to stainless steel in biomaterials applications?

Accepted Answer

Higher cost

Answer

Lower strength-to-weight ratio

Answer

Reduced biocompatibility

Answer

Greater susceptibility to corrosion

Question 17

Which type of stainless steel is commonly used in dental restorations due to its corrosion resistance and aesthetic properties?

Accepted Answer

316L

Answer

304L

Answer

410

Answer

440C

Question 18

Which characteristic of stainless steel makes it particularly suitable for use in surgical implants?

Accepted Answer

Excellent corrosion resistance

Answer

Low density

Answer

High strength

Answer

Biocompatibility

Question 19

A primary advantage of titanium alloys in dental implants is their:

Accepted Answer

Exceptional biocompatibility

Answer

Low cost

Answer

Resistance to corrosion

Answer

High strength-to-weight ratio

Question 20

Which element is primarily responsible for the exceptional corrosion resistance of stainless steel?

Accepted Answer

Chromium

Answer

Iron

Answer

Carbon

Answer

Nickel

Question 21

Which of the following properties makes stainless steel suitable for orthopedic implants?

Accepted Answer

High strength and corrosion resistance

Answer

High ductility and thermal conductivity

Answer

Excellent electrical conductivity and malleability

Answer

Low density and biocompatibility

Question 22

Why are titanium alloys preferred over stainless steel in dental restorations?

Accepted Answer

Titanium alloys have better biocompatibility and osseointegration.

Answer

Titanium alloys are significantly cheaper than stainless steel.

Answer

Titanium alloys are stronger and more resistant to wear and tear.

Question 23

Which type of stainless steel is primarily used in medical implants?

Accepted Answer

Austenitic stainless steel

Answer

Martensitic stainless steel

Answer

Duplex stainless steel

Answer

Ferritic stainless steel

Question 24

Which mechanism contributes to the excellent corrosion resistance of titanium alloys in biological environments?

Accepted Answer

Formation of a protective oxide layer on the surface.

Answer

Presence of specific alloying elements like molybdenum and chromium.

Answer

Titanium's inherent resistance to chemical attack.

Question 25

For a patient with a nickel allergy undergoing hip replacement, which material is most suitable for the implant?

Accepted Answer

Titanium alloy

Answer

Austenitic stainless steel

Answer

Co-Cr alloy

Answer

Any of the above, depending on the specific alloy composition.

Question 26

Which of the following is a limitation of using stainless steel in orthopedic implants?

Accepted Answer

Potential for galvanic corrosion when used with other metals.

Answer

High tensile strength and stiffness.

Answer

Excellent biocompatibility and osseointegration.

Question 27

Which property of titanium alloys makes them particularly suitable for dental implants?

Accepted Answer

High strength-to-weight ratio.

Answer

Excellent electrical conductivity.

Answer

High thermal conductivity.

Answer

Good machinability.

Question 28

What is the primary role of alloying elements in biomedical-grade stainless steel?

Accepted Answer

To enhance its corrosion resistance and biocompatibility.

Answer

To increase its thermal conductivity.

Answer

To improve its electrical conductivity.

Question 29

Which of the following is TRUE about the biocompatibility of titanium alloys?

Accepted Answer

Titanium alloys generally exhibit excellent biocompatibility and are well-tolerated by the body.

Answer

Titanium alloys are easily degraded by the body's immune system.

Answer

Titanium alloys are prone to triggering allergic reactions in patients.

Question 30

When choosing between stainless steel and titanium alloy for a knee replacement, which factor is least likely to influence the decision?

Accepted Answer

The color of the implant.

Answer

The long-term performance and wear resistance of the implant.

Answer

The strength and stiffness of the material.

Answer

The potential for allergic reactions in the patient.