CoCr Framework + HIC/Zirconia
Co-Cr alloy dentures and cast partial dentures have been commonly manufactured since the early 1930s, due tolow cost and arelatively lower density compared to gold alloys. Co–Cr alloys were originally developed for aircraft engines and heat-resistant materials. They show excellent mechanical properties such as strength and toughness, castability, corrosion resistance, and wear resistance. Their corrosion resistance is better than that of stainless steel,and wear resistance is better thanstainless steel and Titanium alloys, but their plasticity and workability are lower than those of stainless steel and Titanium alloys. They were initially used for cast alloys because working on them was difficult. The alloys are generally a combination of cobalt, chromium, and molybdenum, or cobalt, nickel, chromium, and molybdenum. Sometimes, other elements such as tungsten or iron are also used.
The primary Co-Cr alloy used for biomedical and dental purposes is known as Vitallium. Vitallium is an alloy comprising 65% cobalt, 30% chromium, and 5% molybdenum, among other substances. It is used in dentistry and in making artificial joints, because of its resistance to corrosion. Cobalt–chromium alloys, along with nickel–chromium alloys, have been the main base metal alloys used in dental casting. Although the required mechanical properties, such as minimum proof stress of 500 MPa and minimum elongation of 3.0%, are the same for the two alloys, the strength and the hardness of cobalt–chromium alloys are generally higher than those of nickel–chromium alloys. Therefore, cobalt–chromium alloys are mainly used for denture frameworks, while nickel–chromium alloys are applied to crowns and bridges. Co-Cr can now be milled or 3D printed instead of casted, which gives better surface finish and also a standard product.
- Lower density than gold alloys
- Are corrosion-resistant
- Are chemically inert
- Have good biocompatibility
- Have good hardness and tensile strength
- Show excellent wear-resistance
- Yield Strength - 644 MPa
- Ultimate tensile strength - 869 MPa
- Young’s Modulus of Elasticity – 218 GPa
- Dental Implant abutments
- Partial Denture Frameworks
- Fixed Denture Frameworks