General Science Department
I. Test Purpose
This test is used to measure the increase in temperature within a tooth during resin curing.
II. Summary of Test Method
Miniature thermocouples are embedded into a tooth, usually on the surface, within a resin restoration, & in a pulp horn. The tooth is positioned in a 37° C water bath, up to the CEJ, & a curing light positioned over the tooth. When the light is activated, the increase in temperature is recorded.
III. Equipment and Materials
IV. Test method
A. Prepare Tooth:
Note: Keep tooth hydrated at all times, if possible.
1. Cut proximal box prep into tooth using high speed handpiece & bur.
2. Restore tooth with adhesive & composite resin, following manufacturer’s instructions. Prior to curing, place one thermocouple into the resin on the back wall of the prep, place a second thermocouple on the surface of the resin. Cure resin.
3. Place a third thermocouple into a pulp horn by inserting it up the root of the tooth.
4. Verify placement of thermocouples using a digital x-ray system to image the tooth.
B. Prepare Water Bath:
1. Fill water bath with deionized water.
2. Place probe thermocouple into bath & connect to thermometer.
3. Set bath temperature to 37° C.
4. Position tooth in water, up to the CEJ. Use thermocouple wires taped to side of water bath for positioning.
5. Using ring stand with clamps, position light tip over occlusal surface of restoration, 1 mm from tooth.
6. Connect tooth thermocouples to thermometers.
7. Make sure crown of tooth is dry using air syringe.
C. Measure Temperature:
1. Wait for temperatures to stabilize.
2. Activate light, tracking time with timer.
3. Watch thermometers closely. When light turns off, record the maximum temperature displayed on each thermometer. Sometimes the pulp reading will not reach a maximum for several seconds after the light turns off.
4. Record all test parameters: light, tip, tip size, mode, cure time, & maximum temperature at each of the locations within the tooth.
5. Collect multiple data points for each configuration.
6. Perform statistical analysis on data.