An innovative gel that forms a layer over teeth and then recruits calcium and phosphate ions from saliva to build new enamel has the potential to change dental treatment. To date, we don't have any way to regenerate the tough outer layer of enamel on our teeth as it erodes with age.
I could never ever work in that field, it gives me the ick. So I appreciate people who can.
Also enamel is the hardest substance in your body; AFAIK chemically it is indeed interesting and hard (ha) to emulate with other bio-safe materials.