New discoveries have found exceptions to Mendel's basic laws, but none of Mendel's things have been proven to be flat-out wrong. Hail to the Father of Genetics ! The name is ma-ma-ma-ma-ma-Mendel.
Dental crowns should last on average from 10 to 20 years. Crowns are still subject to fracture and cavities, so it is important to take extra care in brushing and flossing around crowned teeth to prevent them from needing replacement too often.
Up to the age of thirteen years, twenty-eight of the thirty-two permanent teeth will appear. The full permanent dentition is completed much later during the permanent dentition period. The four last permanent teeth, the third molars, usually appear between the ages of 17 and 25 years; they are considered wisdom teeth.