The document discusses bioceramics, which are ceramics used in biological applications. It describes various types of bioceramics including bioactive ceramics that bond chemically to bone, bioinert ceramics that are stable in the body such as alumina and zirconia, and bioresorbable ceramics that degrade over time. Requirements for bioceramics include biocompatibility, appropriate mechanical properties, and the ability to bond to or be replaced by bone tissue. The document outlines common bioceramic materials and their applications in orthopedic and dental implants, bone repair, and other medical uses.

1. Introduction about ceramics and
bioceramics
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2. Part II: Introduction about bioceramics
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3. Introduction
 Bioceramic:
• Any ceramic, glass, or glass-ceramic used as a biomaterial,
which is a material intended to interface with biological
systems to evaluate, treat, augment, or replace any tissue,
organ, or function of the body1.
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4.  Bioceramic:
• A large class of specially designed ceramics for the repair and
reconstruction of diseased or damaged parts of the body2.
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5. Forms & Applications
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6. Requirements and critical issues
• 䡧 Geometry.
• Must fill the defects and guide during the regeneration
process.
• 䡧 Bioactivity.
• Rapid tissue attachment and stable long-term bonding .
• 䡧 Biocompatibility.
• Ability to support normal cellular activity.
• 䡧 Chemical & biological stability/ Biodegradability.
• For indefinitely high stability, temporal devices must degrade
gradually and be replace by natural issue.
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7. • 䡧 Porous structure.
• Interconnected porous structure to allow cell penetration and
tissue in-growth.
• 䡧 Mechanical competence/compliance.
• Adequate elastic compliance.
• 䡧 Biological properties.
• Angiogenesis, antibacterial effect, etc by release of
appropriate ions.
• 䡧 Fabrication & Commercialization potential3.
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8. Advantages & disadvantages
of bioceramics:
 Advantages:
• High biocompatibility.
• Less stress shielding.
• No disease transmission.
• High compression strength.
• Wear & corrosion
resistance.
• Low thermal and electrical
conductivity.
• Can be highly polished.
• Unlimited material supply.
• Inert.
 Disadvantages:
• Brittleness.
• Low strength in tension.
• Low fracture toughness.
• High modulus (mismatched
with bone).
• Difficult to fabricate.
• Susceptibility to
microcracks.
• Not resilient4.
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9. Classification of bio ceramics
 1. Based on tissue reaction5:
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10.  2. Based on tissue attachment5
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11. BIOACTIVE CERAMICS
• Bioactive ceramics which form direct chemical bonding with
bone or even with soft tissues in biological medium (i.e. forms
a very strong biological bond after a small amount of
dissolution), examples of these are bioglass, glass ceramics,
calcium phosphates and hydroxyapatite.
 Applications: - Bone void filler. - Middle ear implants. - Dental
implants.
 Properties: - Excellent biocompatibility. - High bone bonding
ability. - Low mechanical strength6.
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12. Bioglass / Glass Ceramics
• Discovery of Bioglass was by Hench and Wilson in 1971.
• The glasses containing specific proportions of silica, sodium
oxide, calcium oxide and phosphorus pentoxide are termed
bioactive.
• The nucleation and growth of crystals within the glass
converts the glass to glass ceramics, which retain the
bioactivity7.
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13.  Typical properties of Bioglass & Glass Ceramic are:
• Nontoxic.
• Chemically bond to bone due to formation of calcium
phosphate surface layer.
• High mechanical strength • Fast setting ability
• Low resistance to tensile and bending stresses
• Extreme brittleness
 Applications:
 - Orthopaedics.
• Filling bone defects.
 - Dental prosthesis.
• Teeth filling.
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14. Hydroxyapaptite
• It is chemically calcium phosphate [Ca10 (PO4 ) 6 (OH)2] and is
similar to the mineral component of bones and hard tissues.
• Hydroxyapatite was successfully used as an implant material
in 1988 soon after the bioactive glasses were developed.
• The hydroxyapatite in powder form is excellent bone filler.
• They have calcium to phosphorus ratio of 1.67 and is the most
stable phase of various calcium phosphates.
• The preparations of hydroxyapatite powders include wet
methods and solid state reactions. Hydroxyapatite is stable in
body fluid and in dry or moist air up to 12000 C and does not
decompose. Plasma sprayed hydoxyapatite was first used by
HERMAN in 1988. It is used as coatings on implants.
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15.  Typical properties of hydroxyapatite are:
• - Biocompatibility.
• - Bioactivity.
• - Capable of creating a direct bond with bone tissue.
• - Noninflammatory.
• - Nontoxicity
 Applications:
• - Artificial bone substitutes in orthopedic.
• - Dental applications.
• It is a valuable material for bone substitution.
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16. BIOINERT CERAMICS
• Bio inert high strength ceramics maintain their physical and
mechanical properties while it is in the host. The term bioinert
refers to any material that once placed in the human body has
minimal interaction with its surrounding tissue. Examples of
these are Alumina (Al2O3), zirconia (ZrO2) and carbon.
 Applications: It is used for knee prostheses and dental
implants …..etc.
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17. Alumina
• Alumina is a highly inert material which was introduced by
Rock in 1933. Alumina exists in many forms and these arise
during the heat treatment of aluminium hydroxide or
aluminium oxy hydroxide.
• ASTM specifies that alumina for implant uses should contain
(99.5 %) of Al2O3 and less than (0.1 %) of SiO2.
 Typical properties of alumina are:
• High hardness • High mechanical strength.
• Minimal or no tissue reaction.
• Good biocompatibility.
• Blood compatibility.
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18. • Nontoxic to tissues.
• Good corrosion resistance.
• Excellent wear and friction behavior.
• The strength of alumina depends on its grain size and
porosity. Generally, the smaller the grains, the lower the
porosity and the higher the strength.
 Applications of Alumina
• Orthopedics: Hip prosthesis ball. Bone screws. Knee
prosthesis. Middle ear implants.
• Dental implants: crowns and bridges.
• Maxillofacial reconstruction7.
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19. Zirconia
• Zirconium dioxide was first extracted from the mineral Zircon
(Zirconium Silicate ZrSiO4 ) in 1817.
• It was found that alloying zirconia with oxides of yttria, calcia
and magnesia made it stable. This led to the use of the so-
called transformation toughening of zirconia to produce
ceramics with unsurpassed crack resistance (‘ceramic steel’).
• Zirconia has some mechanical properties and biocompatibility
better than alumina ceramics; therefore it's represented as an
alternative to alumina.
• It can be used in bulk form or as a coating.
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20.  Typical properties of zirconia are: - High flexural strength. -
High fracture toughness. - Excellent wear resistance. - High
hardness. - Excellent chemical resistance. - Ability to be
polished to a superior surface than alumina
 Applications:
• - Orthopedic and dental implants. - Bone cements. - Coatings
and thin film. - Scaffolds and bone grafts. - Bone repair &
replacement. - Crowns and bridges. – etc.
• One reason for the excellent wear and friction characteristics
of zirconia are attributed to the fact that zirconia has less
porosity8.
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21. Carbon
 Carbon is a versatile element and exists in different forms:
• - Crystalline diamond.
• - Graphite.
• - Noncrystalline glassy carbon.
• - Quasicrystalline carbon.
• However, their brittleness and low tensile strength limits their
use in major load bearing applications. It is used as
biomaterial particularly in contact with blood due to blood
compatibility, no tissue reaction and nontoxicity to cells;
therefore it is used for repairing diseased heart valves and
blood vessels.
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22.  Applications: Due to the good compatibility of carbon
materials with bone and other tissues that carbon is an
exciting candidate for orthopedic implants and used as a
surface coating9.
• None of the three-bioinert ceramics (Alumina, Zirconia and
Carbon) exhibited bonding with the bone. However, the
bioactivity of the bioinert ceramics can be achieved by
forming composites with bioactive ceramics.
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23. BIORESORBABLE CERAMICS
• Biodegradable (bioresorbable) ceramics, as the name
implies, degrade in the host. Bio resorbable refers to a
material that upon placement within the human body start to
dissolve and slowly replaced by advanced tissue (such as
bone), examples of these are tricalcium phosphate ceramics,
coralline.
 They are used for applications such as: - Drug delivery
systems. - Repairing of damaged or diseased bone, bone loss,
- Filling spaced vacated by bone screws. - Repairing herniated
discs. - Repairing of maxillofacial and dental defects.
 Properties: - High compatability. - Low chemical resistance. -
Poor mechanical strength9,10.
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24.  The rate of degradation varies from material to another.
Generally, degradation rate of materials depends on material
composition, and the functions and components of biological
medium.
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25. Calcium phosphate ceramics
• Calcium phosphate ceramics were first commercially used as
implant materials in 1980s.
• They have biochemical composition similar to bone and
exhibit direct chemical bonding to surrounding bone.
Therefore they are used as implant material to be gradually
substituted by newly formed bone and get integrated with the
host bone.
• The first stage is interaction with collagen in bone and then
accumulation of protein and cells on the surface of the
biomaterial and this is followed by the resorption of the
material and finally bone formation11.
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26. • A subclass of these ceramics is tricalcium phosphate ceramics.
They are extensively used owing to its biocompatibility
characteristics. They also have an added advantage of being
resorbable12.
 Other calcium phosphate compounds include:
• -Amorphous calcium phosphate (ACP)
• -Dicalcium phosphate (DCP)
• -Pentacalcium hydroxyapatite
• -Tetracalcium Phosphate Monoxide (TTCP)
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27. References
• 1. Hench LL (1991) Bioceramics: from concept to clinic. Journal of the American Ceramic
Society 74(7)1487–1510.
• 2. Heness G, Ben-Nissan B (2004) Innovative Bioceramics. Materials forum 27:104–114
• 3. Hegde C, Krishna Prasad D, Deepmala S, Rakshith Hegde. Implant restoration materials: An
overview. International Journal of Oral Implantology and Clinical Research 2010;1:43-8
• 4. Karan M, Dua JS, Chawla S, et al: Poly-etheretherketone (PEEK) dental implants: a case for
immediate loading. Int J Oral Implantol Clin Res 2011;2:97-103
• 5. Chauhan CJ, Shah DN, Patel R. Evolution of biomaterials in dental implants part-2. JADCH
2011;2:2-5.
• 6. Muddugangadhar BC, Amarnath GS, Tripathi S, Divya SD. Biomaterials for dental implants:
An overview. Int J Oral Implantology Clin Res 2011-2:13-24.
• 7. Schwitalla A, Muller WD: PEEK dental implants: a review of the literature. J Oral Implantol
2013;39:743-749
• 8. Shrestha S, Joshi S. Current concepts in biomaterials in dental implant. Science Research
2014;2:7-12.
• 9. Saini M, Singh Y, Arora P, Arora V, Jain K. Implant biomaterials: A comprehensive review.
World J Clin Cases 2015;3:52-7.
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28. • 10. Duraccio D, Mussano F, Faga MG. Biomaterials for dental implants: current and future
trends. J Mater Sci. 2015;50:4779–812.
• 11. Prakasam M, Locs J, Salma-Ancane K, Loca D, Largateau A, Berzina-Cimdina L.
Biodegradable materials and metallic implants- A review. J. Funct. Biomater.2017,8,44.
• 12. Deepashree R, Devaki V, Kandhasamy B, Ajay R. Evolution of implant biomaterials: A
literature review. Journal of Indian Academy of Dental Specialist Researchers 2017;4:65-7.
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29. • Thanks
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30. Dental Uses of Bioceramics
 Prosthetic uses
• - implants, prosthesis, prosthetic devices, coatings to
improve the biocompatibility of metal implants (52).
 Surgical uses
• – joint replacements, fill surgical bone defects, alveolar
ridge augmentation, sinus obliteration, and correction of
orbital floor fracture.
 Endodontic uses
• - sealers, obturation, perforation repair, retrograde filling,
pulpotomy, resorption, apexification, regenerative
endodontics.
 Restorative uses
• - Dentin substitute, pulp capping, dentin hypersensitivity,
dentin remineralization
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