Fracture and deformation during tooth processing

In dental restoration manufacturing, zirconia materials are favored for their excellent strength and durability. However, problems such as material breakage and deformation may still occur during processing, sintering and grinding. This article outlines the common causes and solutions to these problems to help technicians optimize production and reduce material waste while maintaining high-quality restorations.

1. Zirconia block breaks during clamping

Cause: The zirconia block is unevenly stressed during clamping.

Solution: Clean up debris under the zirconium block and use 3 to 4 screw fixing points. Tighten evenly and gradually to avoid tightening a single screw too much at a time.

2. Breakage during processing

Cause: Unreasonable layout, excessive vibration of the engraving machine, tool problems.

Solution: Adjust the layout according to the CAD/CAM manual; if the vibration is too large, reinforce and stabilize the engraving machine; if the tool is worn, replace it.

3. Material falls during processing

Cause: Unbalanced layout or incorrect machine parameters.

Solution: Make sure the connecting rod is firm and the layout is balanced, refer to the CAD/CAM manual for proper support; recheck the machine settings to avoid displacement.

4. Fracture during sintering

Reason: Heating or cooling too fast, or furnace temperature too high.
Solution: Adjust the heating rate to the specified curve, control the furnace temperature, control the furnace temperature below 200℃ in summer and below 100℃ in winter.

5. Hidden cracks or fractures during grinding after sintering

Reason: Local overheating or inappropriate tools.
Solution: Use water to cool the material during grinding to avoid local thermal expansion. Use a special zirconia grinding head to reduce heat accumulation, and adjust the speed accordingly.

6. After leaving the porcelain furnace Fracture

Cause: The temperature of the porcelain furnace is too high.

Solution: Reduce the furnace temperature to 600°C or 400°C to prevent material damage.

Tooth deformation problem

1. Loose or tight teeth

Cause: Inaccurate shrinkage, parameter settings or milling machine.

Solution: Check the shrinkage, calibrate the milling machine, and adjust the design parameters as needed.

2. Long bridge deformation

Cause: Layout or sintering curve problem.

Solution: Refer to the long bridge layout suggestions and sintering curve (CAD/CAM manual) for appropriate adjustments.

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