Which function does an insulating base serve in deep cavity preparations?

The function of an insulating base in deep cavity preparations is primarily to protect the tooth from temperature changes. This is crucial because deep cavities can expose the pulp to thermal stimuli, which can lead to discomfort or pain if proper insulation is not provided. The insulating base acts as a barrier that minimizes the transmission of heat and cold to the pulp, helping to ensure the comfort of the patient during and after the dental procedure.

Additionally, by maintaining a stable temperature around the pulp, the insulating base can help facilitate the healing process and reduce the risk of pulpitis. While some other options may relate to functions of certain materials in dental procedures, the protective role against thermal changes is the most significant function of an insulating base in this context.