Final answer:
The material of choice as an insulating base as well as a sedative base is zinc oxide-eugenol (ZOE) due to its soothing effect on the pulp and good insulating properties.
Step-by-step explanation:
The material of choice as an insulating base as well as a sedative base for dental applications would be zinc oxide-eugenol (ZOE). This material is known for its soothing effect on the pulp and its insulating properties, making it suitable for use as a dental base. Calcium hydroxide is another material that is used for its therapeutic effects, such as promoting the formation of secondary dentine, but it is less sedative than ZOE. While glass ionomer cement and zinc phosphate cement are also used in dentistry, they do not have the sedative properties of ZOE.