How the enamel-restoration gel works

James Gallagher stands by four lanes of traffic and inhales exhaust fumes all to see if he can see air pollution in his body. He looks at an intriguing finding that an mRNA vaccine might benefit people being treated with immunotherapy for some cancers and could we be on the cusp of a holy grail in dentistry? A breakthrough could mean we will soon be able to replace the enamel on our teeth. Presenter: James Gallagher Producer: Tom Bonnett Researcher: Thom Hunt Editor: Ilan Goodman