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.
How long do veneers last? Some Stephen Ratcliff, Family & Cosmetic Dentistry smile makeover clients have veneers they received over 15 years ago. (And they still look terrific!) If properly cared for, veneers can last as long as dental crowns.