Tooth loss is a problem that is not unfamiliar to the human species - according to US statistics, only less than 35% of US citizens between the ages of 40 and 64 have all their teeth. The situation is different in the animal world - sharks, for example, can lose up to 30 000 teeth during their lifetime, which simply... grow back. The observations made on these fish - as the scientists from the UK argue - could be key to discovering a way for humans to regenerate their teeth.