Maintaining Dental Four milling machines in perfect working condition is crucial for ensuring their longevity and optimal performance. Careful maintenance before a period of inactivity, such as holidays, and proper preparation upon return are essential to avoid problems and reduce downtime. Here is a detailed guide on how to carry out these operations.

Preparing DF Machines for Downtime

Inside the Machine

• Cleaning the milling chamber: Remove all milling residues to keep the internal environment clean.
• Cleaning the tool holder and tools: Use mineral oil (e.g., Svitol, WD40) to remove milling residues and lubricate the tools.
• Cleaning the camera optics: If present, clean the lens with a soft, damp cloth to ensure clear vision.
• Cleaning the shunk: Clean and lubricate with mineral oil.
• Cleaning the disc holder and clamping system: Disassemble, clean, lubricate, and reassemble the clamping screws.
• Spindle maintenance: Perform complete maintenance and leave a tool loaded.

Inside the Cabinet

• Recirculation tank (if present):
  • Drain the oil/water emulsion.
  • Remove and wash disposable and secondary (blue) filters.
  • Clean the recirculation tank and all internal components.
  • Remove internal residues with a damp cloth.
  • Reassemble the tank and its components, ensuring to reconnect the connector and tube correctly.
• Extractor (if present):
  • Disconnect the extractor’s power supply and disconnect the suction tube.
  • Disassemble and clean the extractor, including the filter bag, sponge filter, and HEPA filter.
  • Clean the inside of the extractor with a damp cloth, let it dry, and reassemble.
• Cooler (if present):
  • Check and refill the liquid level with glycol or distilled water if necessary.

Outside the Machine

• Cleaning surfaces: Clean all external surfaces, including the screen, with a damp cloth and then dry.
• Work table: Remove dust and residues with a damp cloth; for stubborn dirt, use a degreaser.

Restarting DF Machines (First Use)

Recirculation Tank

• Verify the connections of the connector and the emulsion feed tube.
• Ensure the emulsion drain in the tank is closed.
• Restore the emulsion level to 5% with 20 liters of water.
• Insert the blue filters and the disposable filter.
• Check that the machine’s drain tubes are correctly inserted into the upper tank.

Extractor

• Reassemble the extractor components:
  • Insert the filter bag into the container drawer.
  • Check for the presence of the sponge filter in the container lid, then close it.
  • Ensure the HEPA filter is present in the extractor body and lock it with a rotation.
  • Insert the filter drawer into the extractor body and close the compartment.
  • Reconnect the power cable and suction tube.
  • Set the status switch to “auto.”

Milling Machine

• Manually check that the spindle rotates freely with a tool inserted.
• Turn on the machine and open the DF Panel.
• Start a couple of “Spindle Warm-Up” cycles.
• Activate the “pump” button on the “assistance” page and verify that the emulsion exits correctly from the nozzles, adjusting if necessary.