Vacuum Fabrication Instructions


Important: For best results, do not open the foil pouch until ready to use. The Zendura dental appliance sheet must be thermoformed within 15 minutes of opening the protective pouch. (This open time could be reduced in a humid environment.) Store the Zendura sheets packaged and in a cool and dry place.

Cautions: Patients with a history of allergic reactions to plastics should prevent from using this product. Improper thermoforming of the Zendura sheets might lead to the cracking, sharp edges, loose fit or aspiration of the Zendura appliance.

Model Preparation:

  1. The model should be well cured and dry.
  2. The model should be trimmed (or buried with metal granules) to be around 3/4’’—1’’ high. 
  3. Fill in any holes or undercuts with blockout materials and let dry.
  4. Spray the mold with release agent or liquid foil separator to prevent the material from sticking to the mold.

Thermoforming Process:

  1. Pre-heat the machine before using. Pre-heat the vacuum machine for at least 3 minutes. Heating time may vary due to current fluctuations or period of time the heating element is left on.
  2. Place the Zendura plastic (matte surface down that contacts the model)  into the frame of the vacuum machine and the model on the base plate.
  3. After pre-heating, swing the heating element over the sheet.
  4. Observe the plastic as it heats; Zendura sheet should be heated until it sags approximately 1/2 inch.
  5. Move the heating element away from the sheet.
  6. Turn on the vacuum and lower the sheet over the model with a firm force to make sure the plastic holder was fully seated to allow for proper vacuum.
  7. To achieve better vacuum results, a vacuum Gasket (such as Essix #EVM99) can be used to create concentrated sucking power. 
  8. Trim and finish the appliance.


Note: All heaters will heat the plastic at different temperatures because of different heating elements, voltage, hot/cold environment, distance of plastic to the heater, and condition of the heater.  The 1/2 inch in sag of the Zendura plastic will give an ideal thermoformed Zendura appliance over the model.   


Also see Trimming Techniques; Pressure Forming Instructions.