All dinosaurs could regrow teeth.
Plant-eating dinosaurs regrew teeth more quickly (Diplodocus at a pace of one new tooth every 35 days), while carnivorous dinosaurs replaced teeth more slowly.
How often did a typical T. rex replace its teeth?
This means spinosaurs replaced their teeth much faster than other theropod dinosaurs like Tyrannosaurus rex, which replaced its teeth every 777 days.
Did T. rex replace its teeth?
Tyrannosaurus rex replaced its teeth constantly; each tooth perhaps every few years. The replacement tooth grew inside the jaw alongside the root of the functional tooth on the tongue-side of the jaw. A full-sized, but very thin crown formed first (the "germ" tooth) and it grew by adding layers of dentine.
