The gel or thin film contains a peptide known as MSH, or melanocyte-stimulating hormone. Previous experiments, reported in the Proceedings of the National Academy of Sciences, showed that MSH encourages bone regeneration.
Bone and teeth are fairly similar, so the French scientists reasoned that if the MSH were applied to teeth, it should help healing as well.
To test their theory, the French scientists applied either a film or gel, both of which contained MSH, to cavity-filled mice teeth. After about one month, the cavities had disappeared, said Benkirane-Jessel.
Link via Popular Science | Image: NIH