Metal
Cobalt-chrome bridge framework
We made a precisely milled cobalt-chrome framework for an 8-unit bridge supported by 5 natural teeth. The client sent a ready design as STL files with Construction Info, and we produced the structure from a solid Co-Cr disc. The finished framework was passed on for the next stages of work.
01 Challenge
A framework for a bridge on five abutments
A client came to our laboratory needing a precisely made cobalt-chrome framework for an 8-unit bridge supported by 5 natural teeth. She planned to build a zirconia bridge on this framework herself, in her own laboratory.
Three things mattered most: high accuracy of fit, the right rigidity of the structure and a surface the technician can work on comfortably in the next stages.
Order requirements
- Input data: ready design in STL files with Construction Info.
- Material: solid cobalt-chrome (Co-Cr) disc.
- Structure: 8-unit bridge, 5 abutments on natural teeth.
02 Process
Milling from a solid Co-Cr disc
1. Design verification
After receiving the STL files and Construction Info we checked the design and prepared the structure for production.
2. Milling
We milled the framework from a solid cobalt-chrome disc on a 5-axis CNC milling machine.
3. Finishing and quality control
After milling we separated the structure from the connectors, cleaned it thoroughly and put it through quality control. The finished framework was then prepared for shipping.
03 Result
A framework ready for the next steps without adjustments
The framework reproduced the CAD design and was ready for further work without additional adjustments. The client could start on the zirconia bridge straight away.
Milled frameworks offer good repeatability, high strength and an accurate fit, which means comfortable work for the technician and a predictable final result.
04 Why milling
Milling or laser sintering (SLM)?
Compared with structures made by selective laser melting (SLM), milled cobalt-chrome frameworks have several important advantages:
- Precision - accurate reproduction of the design and a tight marginal seal.
- Homogeneous structure - the framework is made from a solid disc, without the layers typical of additive technologies.
- Mechanical durability - high resistance to loads and deformation.
- Predictable processing - milled Co-Cr behaves well during trimming, finishing and porcelain firing.
- Less stress - milling causes no stresses related to local melting of the metal.
- Repeatability - every structure is made with identical production parameters.
05 Summary
Case details
- Type of work: bridge framework, 8 units, 5 abutments
- Material: cobalt-chrome (Co-Cr), solid disc
- Input data: STL files + Construction Info
- Technology: milling on a 5-axis CNC machine
- Further work: zirconia bridge made in the client's laboratory