Types ofBiomaterial

Question

i) What is the differences between bioglass and ceramics, explain it by remembering lecture discussions.

ii) Which generation of biomaterial is bioglass and explain the reason?

iii) What type of biomechanical tests can you perform with bioglasses, provide explanation?

Answer 1

Differences Between Bioglass and Ceramics

Bioglass:

1. Composition: Bioglass is primarily made up of a silicate glass modified with sodium, calcium, and phosphorus oxides. This unique composition allows for bioactivity—meaning it can bond to bone and stimulate biological reactions.
2. Bioactivity: One of the key features of bioglass is its ability to form a bond with bone tissue. When in contact with body fluids, bioglass undergoes a surface reaction to form hydroxyapatite, mimicking the mineral component of bone and facilitating biological integration.
3. Resorption: Bioglass exhibits a controlled resorption rate in the body, which allows for gradual substitution of the material by natural bone over time. This property is beneficial for bone regeneration and healing.

Ceramics:

1. Composition: Ceramic biomaterials can be composed of various inorganic materials, including calcium phosphates (like hydroxyapatite), aluminum oxides, and others. They can be crystalline or partially crystalline in structure.
2. Inertness: Many ceramics, like alumina and zirconia, are bioinert, meaning they do not elicit a significant biological response or bond with surrounding tissue. Their primary function is to serve as a physical barrier or support structure rather than actively participating in tissue integration.
3. Mechanical Properties: Ceramics generally have high compressive strength and wear resistance, but they can be brittle and susceptible to fracture under tensile load.

Generation of Biomaterial for Bioglass

Bioglass belongs to the 2nd generation of biomaterials.

Reason:

1. The classification of biomaterials into generations is based on their development, functionality, and interaction with biological systems:
2. 1st Generation: Involves inert materials (like metals and ceramics) that merely act as scaffolding for tissue.
3. 2nd Generation: Focuses on bioactive materials that can form bonds with bone and promote healing, like bioglass, which stimulates tissue regeneration and integrates biologically with the surrounding environment.
4. Bioglass was developed to enhance the integration process and promote osteoconductivity, making it a significant advancement over non-interactive materials.

iii) Biomechanical Tests for Bioglasses

Several biomechanical tests can be performed on bioglasses to assess their properties and performance:

1. Compressive Strength Testing:
2. Purpose: To evaluate the material's ability to withstand axial loads without failure.
3. Explanation: Since bioglasses are often used in load-bearing applications (like bone repair), measuring compressive strength helps determine if the material can support physiological loads in vivo.
4. Tensile Strength Testing:
5. Purpose: To assess the material's resistance to tension across a defined cross-section.
6. Explanation: Although bioglasses are not typically used in tension, understanding tensile properties can help predict behavior under complex loading conditions, especially when composite materials are involved.
7. Flexural Strength Testing:
8. Purpose: To measure the material's response to bending forces, which is crucial for applications where bioglass is used as a support structure.
9. Explanation: This test provides insight into how the material can handle flexural loads and helps predict its performance during application, particularly in implants.