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.
After reading that article, this feels like something that I would want a trained professional to oversee.
Maybe similar to fluoride, there can be a low-concentration version OTC, with the strong professional version only being available directly.