The experiment was performed to clarify the effect of temperature on pulp during impression taking with modelling compound, alginate and plaster of paris.
Mongrel dogs were anesthetized with nembutal, 30㎎/㎏body weight.
In order to measure the pulpal temperature, an inserting hole was prepared on the cervico-labial surface of each canine tooth and a thermister probe (diameter in 23 gauge) was inserted into pulp chamber and connected to a carrier preamplifier(Narco Biosystem Co.).
The change of pulpal temperature during impression taking was recorded on the physiograph that had calibrated under standard temperature.
The impression was taken with modelling compound, alginate and plaster of paris by using the temporary aluminum crown. Alginate was mixed with 10.0℃ and 20℃water and plaster of paris was also mixed with 20¡ÆC water as a routine method.
The obtained results were as follows:
1. Taking the impression with modelling compound, temperature rise of pulp was 4.85±1.31℃ and normal temperature of pulp was 33.2±1.15℃.
2. When impression taking was prepared by using the alginate mixed with 10.0℃ and 20℃ water, decrease of pulpal temperature was 3.01±0.89℃ and 2.14±0.71℃, respectively.
3. When plaster of paris was used as an impression material, time to maximum change of pulpal temperature was not significant.
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