Can teeth grow back like nails ?

 

With an average rate of 1 to 3 mm per month, toenails and fingernails grow back constantly. Their growth begins in the nail matrix, an area located under the skin, just at the base of the nail. Within this matrix, new cells appear and move outwards, hardening, until they form the visible nail. Nails renew themselves indefinitely as long as the matrix is intact.

When it comes to teeth, the system is very different. Although a tooth can regenerate, it is a slow process which does not occur systematically and mainly applies to small lesions.

Composition and appearance of teeth in the mouth

Three types of tissue make up the tooth. Enamel is the hard, external part that protects the tooth. Dentin, softer, is located under the enamel. Finally, the pulp is the innermost part of the tooth, which contains the nerves and blood vessels. It is she who is responsible for tooth growth.

Even before birth, teeth begin to form. Milk teeth appear during fetal life, with the germs of permanent teeth. 20 primary teeth will thus emerge into the child's mouth. They will gradually be replaced by 32 permanent teeth, larger, more robust and more deeply anchored in the jaw.

When a tooth breaks, it does not grow back. Medical intervention is necessary to restore the integrity of the tooth. The dentist can glue the broken piece back together, fill the crack with an artificial resin, or even use devices such as an implant, bridge or veneer.

Dental regeneration, a perspective to explore

While sharks and crocodiles are able to regenerate their teeth throughout their lives, thanks to the emergence of new germs in the gums, humans do not have this possibility. However, our species has a capacity for tooth regeneration which sometimes manifests itself during small-scale lesions. It actually relies on stem cells present in the tooth, considered dormant most of the time, and which can wake up to stimulate the repair of enamel, pulp and dentin.

Based on studies in mice, stem cells respond to dopamine and serotonin released when the tooth is damaged. Blood platelets actually release these neurotransmitters in the presence of a dental lesion. Dopamine and serotonin activate stem cells in the tooth pulp and stimulate tooth regeneration.

This perspective is one of the most promising avenues for the future of dental care, and could lead to self-induced tooth repair in affected patients.