VOA慢速英语:Drug Helps Teeth Repair Themselves

dentist – n. a person whose job is to care for people's teeth

dental – adj. of or relating to teeth or to the work dentists do

dentine – n. a calcareous material similar to but harder and denser than bone that composes the principal mass of a tooth

cavity – n. an area of decay in a tooth

porcelain – n. a hard, white substance that is very delicate and that is made by baking clay

sponge – n. a piece of light natural or artificial material that becomes soft when it is wet, is able to take in and hold liquid, and is used for washing or cleaning

stimulate – v. to make (something) more active

dose – n. the amount of a medicine, drug, or vitamin that is taken at one time