Protocol-Color Comparison of Try-in Paste to Cured Cement

  1. OBJECTIVE

    2. Compare the shade of the a cement to its corresponding try-in paste and determine the accuracy of the match.

  2. EQUIPMENT

    1. Digital camera (FinePix F1 pro by Fuji)
    2. Camera lens (Nikkon, AF Micro Nikkor, 105mm, 1:2.8D)
    3. 2 photography lights (Powerlight 1250)
    4. Pipette M250 with pistons and tips
    5. Microscope slides (75x25x1mm)
    6. Micro cover glass (No. 1, 24x60mm)
    7. Ivoclar mixing pads
    8. Standard color grid
    9. Photoshop (latest version)
    10. Printer (Epson Stylus Photo R200)
    11. Printing Paper (Epson Premium Glossy photo paper, S041667)
    12. Optilux 500 halogen curing light (Intensity ≥300mW/cm²)
    13. ShadeEye NCC (Shofu Inc.)

  3. METHOD

    4. Camera Settings: Manual, F9.5, 1/250
    Light Settings: Mode: manual, both switches all the way to the left (1/32)
    Photoshop Settings:
    Edit→color settings→settings: North American General Purpose Defaults
    Image→Mode→CMYK Color
    Ctrl+1→Channel: CMYK, input levels: 0, 1.00, 255, output levels: 0, 255
    ShadeEye NCC Settings: whitening, chose any tooth

    1. Place Ivoclar mixing pad on table.
    2. Place microscope slides on mixing pad, with color grid on top of the lower microscope slide. (See image 1)

      3. Image 1 (click to enlarge): Ivoclar mixing pad underneath 2 micro slides, spaced 15-20 mm apart. Bottom micro slide has color grid for adjusting white, grey, and black color levels in Photoshop.

    3. Using pipette, dispense 0.8 ml of cement between microscope slides, above the color grid and to the left. (See image 2)

      4. Image 2 (click to enlarge): 0.8 ml of cement has been placed above the color grid and to the left.

    4. Dispense 0.8 ml of try-in paste between microscope slides, above the color grid and to the right. (See image 3)

      5. Image 3 (click to enlarge): 0.8 ml of try-in paste has been placed above the color grid and to the right.

    5. Place micro cover glass on cement and try-in paste and press down. Horizontal edges of cover glass should overlap both microscope slides. (See image 4)

      6. Image 4 (click to enlarge): Cover glass has been placed on top of cement and try-in paste. Cement is ready to be cured.

    6. Cure cement for 40 seconds with Optilux 500 curing light.
    7. Measure shade of cement and try-in paste with ShadeEye NCC. Take measurements by placing tip of ShadeEye NCC on micro cover glass over the specimen. Record both the Classic and the Vita 3D readings.
    8. Take picture of samples with digital camera, using AF Micro Nikkor lens and photography lights. Lights should be placed symmetrically to minimize shadow.
    9. Import picture into Photoshop.
    10. Adjust white, grey, and black color levels using Photoshop software and color grid in picture. (ctrl+L will open the level adjusting window)
    11. Save the image and label it <pic number>adj.jpeg. Adj means the images's color levels were adjusted.
    12. Print image on Epson Premium glossy photo paper with Epson Stylus Photo R200 printer.

  4. RESULTS

    1. Verify that the color grids show similar colors from one picture to the next.
    2. Compare data from ShadeEye NCC to determine accuracy of match for cured cement and corresponding try-in paste shade. Grade picture using the following scale:

      3. E = Classic and Vita 3D match exactly
      G = Classic matches and part* of Vita 3D matches --or-- Vita 3D matches but Classic does not
      F = Classic matches but no part* of Vita 3D matches --or-- part of Vita 3D matches but Classic does not match
      P = Classic and Vita 3D do not match

    3. Have 3 evaluators examine printed images to determine accuracy of match.

    *Note: "Part" of the Vita 3D refers to the value, hue, chroma and readings. When comparing the Classic scale, do not consider any parts. Either the Classic matches exactly or it does not get counted as a match.