Impressions

Taking good impressions requires some patience, but nothing is more critical to the success of your appliances. We offer the following guidelines as a reference, hands-on instruction is essential to your success. Please don’t hesitate to contact us with your questions. We have courses at Eubank Teaching Institute to train you and your staff in the proper method of taking impressions and performing the E-tab procedure.

Taking Impressions

  1. Before you begin taking the impressions, explain to the patient what you will be doing (how many impressions, how long each one takes to set up, whether the material is hot or cold, etc.) The patient will be willing to help you as long as she knows what is going on.
  2. Test the tray size first before you begin loading the tray.
  3. Have the patient close on a folded C-fold towel to absorb any saliva on the occlusal surfaces. Have the patient keep her mouth open to keep the teeth dry.
  4. Inject the impression material on the occlusal surfaces of the teeth and place the loaded impression tray in the middle of the patient’s face.
  5. While you are taking the upper impression, have the patient hold the impression tray with her thumb in the middle of the tray. If you are dealing with a sensitive patient, you may need to hold the tray yourself.
  6. When you are taking the lower impression, have the patient close down to hold the tray in place (if she can). You may need to hold the tray yourself.
  7. If the patient has toris (mandibular or maxillary exostosis) you will need to place more impression material in the tray.

Pouring Impressions

  1. Rinse the impression in cool water and blow out the excess water.
  2. While holding the impression, spray surfactant at arms length. Do not spray too much, for this will cause the model to be soft and brittle. If you notice that the surfactant is pooling in certain areas, be sure and blow it out.
  3. If you are using Hydrocolloid, never lay the impression flat on the counter – prop the impression up with a lab knife or a spatula. This will prevent the impression from distorting.
  4. Mix together 120 grams of Die Keen Green and 25 ml of Stalite. Mix together until the mixture becomes smooth.
  5. Slowly add the mixture in the impression starting on the palate. Watch the mixture flow into the teeth. Carefully monitor the impression as you pour – if the mixture flows too fast it will trap air bubbles.
  6. Pour the leftover mixture into a C-fold towel to absorb the moisture.
  7. Roll the material in your hand and place on top of the impression. This will make a base. If you do not have enough leftover material, you can add stone to the mixture to make the base.
  8. To prevent the mixture from running out the back of the tray, cut 2 pieces of c fold towel and place on each side.
  9. The material needs to set for at least 2 hours before removing and trimming.
  10. To add a thicker base, use the Redi-base molds with mounting stone.

Hydrocolloid Instructions
Supplies needed from Sullivan and Schien:

  • B-Tron 101 Hydrocolloid Unit
  • Van R Water Cooled Trays (various sizes)
  • Gray Rubber Tubing for Trays (# 135-2285)
  • Slate (Special Pacific Blend)- Tray Material
    • 12 per box (# 135-2921)
    • 144 per box (# 135-5021)
  • Regular-Red ( use in the back loading syringe)
    • 12 per box (# 135-0791)
    • Kerr Free-Flo Syringe (back loading syringe)
      • (# 123-5761)

Procedure

  1. The B-Tron unit 301 should be set on the following temperatures:
    • Right – 153 (this is the tank to boil the slate for 10 minutes)
    • Middle – 153 (storage tank for slate after it has boiled)
    • Left – 110 (the impression should stay in this tank for 5 minutes)
  2. The B-Tron unit 101 should be set on the following temperature:
  3. Boil the Red for 20 minutes and the temperature should cool down to 157. Leave the red in this tank always. TIP: After the material has boiled, leave the lid open so the material can cool down faster
  4. Load the tray with the slate material and place in the storage tank (110) for 5 minutes. After the timer goes off, load the back loading syringe. Place the red material around the teeth and put the tray in the mouth for 4 minutes.