Background:
Due to their properties, composite materials have gained many applications. However, light polymerization leads to an increase of intrapulpal temperature during the curing process. Many contributing factors are considered, including composite colour.

Aim of the study:
To check the influence of the colour of the composite material during its polymerization on the temperature increase in the pulp chamber.

Material and methods:
In the third molar with a prepared flat occlusal surface, a K-type thermocouple was installed under radiological control. The location of the thermocouple and the thickness of the dentine were checked on micro-CT images. A composite material in A2, B2, and C2 colours was placed in a specially prepared matrix, and then it was irradiated with a polymerization lamp in a continuous operation mode for 20 seconds. The temperature in the tooth chamber was measured in real-time with a frequency of 1 second.

Results:
There were no significant differences between the colours in the case of maximum temperature amplitude and temperature amplitude in the 20th second of exposure. Only the time to reach the maximum temperature during polymerization differed significantly between the A2 and C2 colours.

Conclusions:
The colour of the composite is of little importance as a factor influencing the temperature increase in the tooth chamber.