Protocol-Flowability of Veneering Cements

  1. OBJECTIVE

    2. Measure the flowability of cements and other light-cured materials.

  2. EQUIPMENT
    1. Clear Acrylic Sheet, approx. 6mm thick, Acrylite FF by Cyro Industries
    2. Marker
    3. Pipette Microman M250, with pistons and tips
    4. Straight edge ruler
    5. Calipers
    6. Halogen light curing device (Intensity ≥ 300 mW/cm²)

  3. METHOD

    1. Draw a horizontal line on the clear acrylic sheet parallel to bottom edge to serve as a guildline. Cement will be dispensed on the opposite side of sheet.
    2. Attenuate room lights to minimize premature light curing.
    3. Draw 0.1 ml of cement into pipette tip and dispense cement onto a point on the guide line. Repeat for each sample.
    4. Position the acrylic sheet vertically, with the guideline horizontal for five minutes. (See figure 1)
    5. At the end of 5 minutes, immediately return plastic plate to horizontal position.
    6. Cure each sample for 60 seconds using halogen light curing device.
    7. Illuminate room light and measure the distance from the highest point of the sample to the lowest using staight edge ruler and calipers.
    8. Measurement with straight edge ruler: flip acrylic sheet and measure sample perpendicular to the guideline.
    9. Measurement with calipers: flip acrylic sheet back to the side with the cured cement samples and measure sample perpendicular to the guideline.
    10. Repeat step 2-9 four more times for a total of five samples of each cement brand. Test more than one shade to insure that flow is not affected by shade choice.

    Figure 1: Acrylic sheet in vertical position with guildline (red) and cements (yellow).

  4. RESULTS

    5. Calculate the average distance traveled over the five assays for each brand of cement.