How many sets of teeth do adults have?

Adults have two sets of teeth: the primary (deciduous) teeth and the permanent (secondary) teeth. The primary teeth start to erupt when a baby is about 6 months old and are usually all in place by age 3. There are 20 primary teeth in total. The permanent teeth start to erupt around age 6 and are usually all in place by age 32. There are 32 permanent teeth in total.