1. Composite and Functionally Graded Materials of Ti/HA for Dental Implants
Presentation By:
Assist. Prof. Dr. Jawad K. Oleiwi
Assist. Prof. Dr. Rana A. Majed
Lec. Dr. Sura A. Muhsin

2. Aim of the work
This work focuses on the dental bioimplants, to produce dental fixture as a bioimplant instead of titanium or stainless steel with best properties, since the functionally graded material and composite of (Ti/HA) is the best selection. This fixture with height (10 mm) is implanted with the jaw bone and contact with the tooth by abutment.

3. Screw implants and Cylinder implants
The benefits of composites are mostly in weight and cost, measured in terms of ratios such as stiffness/weight, strength/weight.
The main characteristic that distinguishes functionally graded materials FGM from conventional a composite material is the tailoring of graded composition and microstructure in an intentional manner. That gradation aimed to design the distribution of properties needed to achieve the desired function.
Screw implants and Cylinder implants

4. Introduction
The materials suitable for implantation are those that are well-tolerated by the body and can withstand cyclic loading in the aggressive environment of the body. Biocompatibility, an essential requirement for any biomaterial, implies the ability of the material to perform effectively with an appropriate host response for the desired application.

5. Limitation of Materials and Problem
The limitations of metals
-They are susceptible to chemical and electrochemical degradation.
-The implant materials may corrode and/or wear, leading to the generation of particulate debris, which may in turn aggravate the body environment and elicit both local and systemic biological responses.
The limitations of ceramic materials
-Their low tensile strength and fracture toughness.
-Their use in bulk form is limited to functions in which only compressive loads are applied.

6. Inflammation inside the bone
Corrosion of screw
Inflammation inside the bone

7. Solution
To Reduce the problem of corrosion in dental implant , we suggested to fabricate Functionally Graded Material (FGM) and composite material consists of biometallic (Ti) and bioceramic (Hydroxyapatite). In addition to solve the problem of galvanic corrosion between screw and abutment.
Prosthetic Crown
Abutment
Dental Implant

8. Experimental Procedure
Fabrication of
Materials
Ti/HA
FGM and Composite
Characterization of Materials
XRD, SEM and EDS
Study the Hardness and Compressive Strength
Test Corrosion Behavior
OCP, Linear and Cyclic Polarization
Test the Biocompatibility

9. Design of FGM and Composite
Metal Layer
FGM Layers with different volume fraction.
Ceramic Layer
Design of five layers FGM
Ti/HA composite

10. Results
and Discussions

11. Characterization of Fabricated Materials
X-Ray Diffraction
XRD pattern of titanium powder.
XRD pattern of Hydroxyapatite powder.

12. Ca5(PO4)3(OH), Ti4P3, CaO, Ca4O(PO4)2 and β-TCP.
XRD pattern of FGM
XRD pattern of composite
Ca5(PO4)3(OH), Ti4P3, CaO, Ca4O(PO4)2 and β-TCP.

13. Microstructure and Chemical Composition Examination
SEM image for titanium.
SEM image for hydroxyapatite.

14. SEM image for three layers in FGM

15. SEM image for composite

16. EDS analysis for first layer (100%Ti) of FGM
EDS analysis for fifth layer (100%HA) of FGM

17. EDS analysis for second layer (75% Ti-25%HA) of FGM
EDS analysis for third layer (50%Ti-50%HA) of FGM
EDS analysis for forth layer (25%Ti-75%HA) of FGM

18. EDS analysis for composite sample

19. Mechanical Properties Microhardness of Ti/HA as composite is 350 MPa
Microhardness of FGM

20. Compression Compressive strength FGM and Composite
The compressive strength of all dental alloys is sufficiently high that it is not a consideration for clinical performance; however, tensile strength varies considerably among alloys.
The compressive strength of fabricated FGM and composite was 110 and 115 MPa and approximately approaching to the compressive strength of human bone (170 MPa).
Compressive strength FGM and Composite

21. Results and Discussions of the Modulus of Elasticity
The elastic modulus of Ti/HA composite is
The elastic modulus for FGM

22. Design of Screw implant

23. Fixture of FGM implant in the bone

24. Results and Discussions of Numerical Part
Contours of Total Deformation Distribution
Total deformation distribution
of FGM

25. Total deformation distribution
of composite

28. composite, stainless steel and titanium.
Total deformation distribution of FGM,
composite, stainless steel and titanium.

29. Contour of Equivalent (Von Mises) Stress of FGM

30. Contour of Equivalent (Von Mises) Stress of composite

33. Corrosion
Corrosion is the deterioration of metals by chemical interaction with their environment. It is a normal electrochemical process. Corrosion is one of the major processes affecting the life and service of orthopedic devices made of metals and alloys used as implants in the body. No metallic material is totally resistant to corrosion or ionization within living tissues.

34. Electrochemical Properties
Potential – time measurements
for pure Ti and fabricated Ti/HA
at in Ringer’s solution.
Tafel plot for pure Ti and
fabricated Ti/HA .

35. Corrosion Parameters
17.71
6.20
4.22

36. Ti/HA composite Ti/HA FGM
Ebd= mV
ibd=14.4 mA/cm2
Epit=-460.8mV
ipit=2.0 mA/cm2
Cyclic polarization of pure Ti and fabricated Ti/HA materials.
Ti/HA composite
Pure Ti
Ti/HA FGM
Optical microscopy of corroded surface.

37. Biocompatibility
Biocompatibility is mainly determined by the implant surface properties. When a metal implant comes in contact with biological tissue, the following occurs:
1. The implant is first covered with proteins from the body fluids, then cells may attach according to the implant surface properties.
2. A biocompatible implant will be tolerated by the body or a foreign body reaction will occur. For metals, this depends on the surface properties of the implant, such as surface chemistry and roughness. Proteins and cells interact differently on surfaces with different properties. If the implant is biocompatible, the inflammation will decrease.

38. Conclusions
- The mechanical properties (microhardness, compression) of Ti/HA FGM and composite samples gave values approach to mechanical properties of bone.
- The values of modulus of elasticity also approach to the modulus of elasticity of human bone.
The total deformation occurred in the functionally graded and composite samples were closed to other known biomaterials.
Corrosion properties were better than that for pure Ti in artificial human body fluid.
The biocompatibility test of Ti/HA FGM and composite samples gave good absorption to culture cells.

39. Suggestion and Recommendation
For future work, the following are suggested and recommendations:-
1. Study corrosion for FGM and composite samples in saliva media.
2. Use spark plasma sintering (SPS) in the fabrication of FGMs and composite samples.
3. Study other properties such as fatigue and shear bonding between layers of FGMs samples.
4. A comparative the biological behavior for Ti/HA FGMs and composite samples in vitro.
5. Use other materials in dental implant like Mg/HA.
6. Evaluation the addition of Iron to the Ti/HA FGMs and composite which influences the biological behavior of the composites in the simulated body fluid.

40. Thank you for listening