The Pure-Press Restoration: Step By Step

Flemming Behrend, MDT · Technical · Mar 2008

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 4:** For a matrix, I applied a bonding agent between the porcelain and metal and fired the restoration.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 6:** The number of press pellets used for each restoration is relevant to the weight of the full contour waxup minus the weight of the opaqued copings. After each measurement was accurately noted, I knew exactly how many pellets to use for the four anterior crowns. (Most manufacturers will inform you of the correct relationship between wax weight and number of press pellets.)

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 7:** After burnout at 900°C for 40 minutes, I pressed the crowns at 940°C and allowed them to cool down to room temperature. I opened the mold by first drawing a line at the height of the plunger, marked a horizontal line at the correct height and used a diamond separating disc to cut along the line. Then I used a knife along the vertical edges to separate the mold.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 1:** I waxed up the ideal shape of the four anteriors on a duplicate model of the patient’s existing teeth.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    After

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 2:** I fabricated models and blocked out the dies. I also made an index from the anatomical waxup on the pre-op model to help later with the full contour waxup.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 5:** I then fired opaque onto the surface of the pure gold copings.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 8:** To further devest, I blasted with 50-micron glass beads, first at 6 bar pressure and then at 1.5 bar pressure on the copings.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    Before

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 9:** I cut the pressed crowns with an all-diamond disc and seated them on the model for final contouring.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 3:** I duplicated the dies for electroforming and then placed them in a plating head and processed overnight; the thickness of the final copings is 0.2 -0.3 mm.

  • Flemming Behrend, MDT

    Owner at Flemmings Dental Ceramic Studio Inc.

    **Step 10:** To obtain a natural glaze, I polished the surface with fine conical diamonds, then used a non-contaminating white silicone rubber point and finished with a leather wheel saturated with white tin oxide. After the surface appeared nice and smooth, I ran the crowns through a glaze bake with a minimum amount of stain liquid applied.

Show More