1. Implant: مادة سنية / د . زينة ثاني اسنان موصل 12 / 4 / 2016
Is a material or device placed in and or on oral tissue to support oral prostheses. Implant materials: 2 basic classes of materials 1- ceramic 2- metal

2. Implant properties Implant material can be classified according to:
- Physical, mechanical, chemical and biological properties.
These properties include elastic modulus, tensile strength and ductility to determine optimal clinical application.
- metal posses high strength and ductility.
- ceramic and Carbone are brittle materials.

3. A- metallic implant
1- Titanium is the most implant material used The American society for testing and materials (ASTM) For surgical implants recognizes four grades of commercially pure titanium and two titanium alloy 1- Cp titanium grade I ( 0.18 oxygen) 2- Cp titanium grade II ( 0.25 oxygen) 3- Cp titanium grade III( 0.35 oxygen) 4- Cp titanium grade IV ( 0.40 oxygen)

4. metallic implant:
Ti and Titanium alloys most commonly used named Ti-6Al-4V and Ti-6Al-4V extra.
Ti-6Al-4V most commonly used.
Modula of elasticity of it is closer to the bone than any other material.
This produce most uniform distribution of stress along the bone implant surface.

5. Advantages
1- high degree of compatibility 2- high strength 3- high corrosion resistance Disadvantages 1- high cost 2- difficult and dangerous to cast

6. 2- Cobalt chromium molybedinium alloy
Composition of this alloy consist of 1- cobalt 63% 2- Chromium 30% 3- Molybedenium 5 % 4- carbon ,manganese and nickel traces

7. Advantages
1- low cost and easy fabrication 2- when properly fabricated show good biocompatibility Disadvantages 1-poor ductility

8. Stainless steel : composition
1- chromium for corrosion resistance 2- nickel to stabilize structure 3- iron 4- carbon Properties 1- high strength and ducility so resist brittle fracture, Easy fabrication and high tensile strength.

9. disadvantages B- ceramic and ceramic coated implant materials:
1- galvanic potential
2- susceptible to pit and crevice corrosion
B- ceramic and ceramic coated implant materials:
Ceramic implant are of two types
1- bio inert aluminum oxide
2- bio active hydroxy appetite

10. General properties of ceramic
1- high compressive strength up to 500 mpa 2- less resistance to shear and tensile strength 3- brittle

11. Advantages:
1- excellent biocompatibility. 2- color is similar to bone, enamel and dentine. 3- minimal electrical and thermal conductivity. Disadvantages: 1- low tensile ,shearing and mechanical strength under fatigue. 2- low attachment strength for some coating with substrates.

12. Polymer:
First used in 1930 s. Not used now a day, because of low mechanical strength And susceptibility to fracture during function. Sterilization by only gamma radiation. Contamination of polymer.

13. Selection of implant material
1- important consideration is strength of material and type of bone to be placed. 2- anterior implant designated for use in narrow space have smaller diameter. 3- single implant in posterior area have larger diameter.