Cobalt-chromium (CoCr) is a metal alloy that has been a cornerstone of dental technology for decades. Known for its exceptional mechanical strength, corrosion resistance, and biocompatibility, CoCr is widely used in frameworks for removable and fixed dental prostheses. With the rise of digital workflows, the material has evolved from traditional casting alloys to highly precise CAD/CAM-milled and laser-melted variants.
Cobalt-chromium alloys consist mainly of cobalt (Co) and chromium (Cr), with smaller amounts of molybdenum (Mo), tungsten (W), and other elements to optimize performance. The chromium content (typically 25–30%) forms a stable oxide layer that protects the alloy from corrosion. Molybdenum and tungsten enhance hardness and wear resistance, while cobalt provides toughness and elasticity.
Key properties of CoCr alloys include:
High strength and rigidity – suitable for long-span restorations and partial dentures
Excellent corrosion resistance – due to the passive chromium oxide layer
Good wear resistance – ideal for occlusal surfaces and mechanical load zones
Thermal stability – resistant to deformation during porcelain firing
Biocompatibility – safe for intraoral use when properly processed
CoCr alloys are a standard material for frameworks in both fixed partial dentures (bridges) and removable partial dentures (RPDs). The combination of rigidity and low weight ensures long-term durability and patient comfort.
In metal-ceramic (PFM) restorations, CoCr serves as a strong substructure for veneering porcelain. The alloy’s high melting point and low thermal expansion coefficient make it compatible with ceramic firing processes.
Cobalt-chromium is also used in implant frameworks, bar constructions, and suprastructures. CAD/CAM and laser-melting technologies allow for precise, custom-fit designs with minimal distortion.
Due to its hardness and resistance to deformation, CoCr is employed in certain orthodontic wires, clasps, and precision attachments. It maintains elasticity over long-term mechanical use.
Traditionally, CoCr frameworks were produced via the lost-wax casting technique. However, casting requires precise temperature control and careful handling due to the alloy’s high melting point (around 1,400 °C).
Modern dental laboratories increasingly use pre-sintered or fully dense CoCr blanks for milling. CAD/CAM technology ensures high precision, consistent material quality, and reduced post-processing.
Additive manufacturing has revolutionized CoCr processing. Laser-melted CoCr frameworks exhibit fine microstructures, excellent fit accuracy, and reduced material waste. This process also supports complex geometries and lightweight lattice designs.
Outstanding mechanical strength and long-term stability
Resistant to corrosion, wear, and heat
Cost-effective alternative to precious metal alloys
Suitable for both traditional and digital manufacturing methods
Excellent compatibility with ceramics for veneering
Higher rigidity can make adjustments more difficult than with gold alloys
Possible allergic reactions in rare cases (due to nickel traces or processing residues)
Requires specialized equipment for melting and polishing
Metallic color limits use in highly esthetic anterior regions
The future of cobalt-chromium lies in advanced manufacturing and digital integration. Additive processes are continually improving surface quality, density, and precision, while optimized alloy compositions enhance biocompatibility and reduce hardness for easier processing. Combined with fully digital CAD/CAM workflows, CoCr remains a robust, economical, and reliable solution for modern prosthetic dentistry.
Cobalt-chromium has proven itself as one of the most versatile and reliable materials in dental technology. Its excellent mechanical performance, corrosion resistance, and adaptability to modern digital workflows make it indispensable for frameworks, implant prosthetics, and hybrid restorations. As technology advances, CoCr continues to bridge the gap between traditional metal craftsmanship and state-of-the-art digital dentistry.