This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
Which of the following materials is the most ideal for
indirect pulp capping? 
Select and explain. 
A. Calcium hydroxide, B. Zinc oxide eugenol cement, C. Zinc oxide powder only, D. Zinc oxyphosphate cement
A: Calcium hydroxide
Answer: A: Calcium hydroxide 
Explanation: Calcium hydroxide remains the standard material for pulp capping of normal vital pulp tissue; it can possibly stimulate the repair reaction. A hard-setting calcium hydroxide capping material should be used. If the tooth is small (such as a first primary molar), hard-setting calcium hydroxide may also be used as the base for the restoration.  Some  studies  have  shown  successful  results  with direct capping of exposed pulps with adhesive bonding agents,  whereas  others  have  reported  pulpal  inflammation  and  unacceptable  results  with  this  technique.
McDONALD AND AVERY’S DENTISTRY  CHILD   ADOLESCENT 10thEd P:228