Britain's Worst Teeth follows four twenty-somethings with some of the worst teeth in Britain. Their teeth are so bad they affect every aspect of their lives. They are in pain, they are embarrassed to go out, they find eating and speaking difficult, they find it difficult to attract partners.

All might not be lost. Three of Britain's top dentists have agreed to take on these four cases and see if they can do anything to save their terrible teeth.

20 year old Sarah is addicted to sugar. On top of all the sweets and chocolate she eats, she has 4 teaspoons of sugar in tea and coffee and 3 tablespoons on her cereal. Add in the fact that she hasn't seen a dentist since her early teens and it is little wonder that her teeth are falling apart. Cracks and huge cavities ravage her mouth. 'Sometimes I look in the mirror and think. Slim, nice hair, look good and then I look at the teeth and whatever I am feeling just goes. They just ruin it.' Sarah hasn't had a boyfriend in over a year and knows her teeth are hindering her chances. Now she has decided she has to act.

Gemma Lundy began to loose her teeth when she was 16. Her problem is not decay. For 10 years she suffered from bulimia nervosa. Throwing up ever day has eroded Gemma's teeth away. Now 24 with a new baby, she has conquered her eating disorder but 80% of her tooth enamel has disappeared. She is desperate to get her teeth back but has no idea if anything can be done.

Brother and sister Paul and Genna Leach are petrified of the dentist. Both recall horrific dentist experiences as children, the memory of which has stopped them from having all but emergency treatment for the last 10 years. Still in their early twenties, their teeth are literally rotting in their mouths. Their gums are covered in abscesses. Tooth brushing is a selective business. Both are in so much pain that they rely on a constant diet of pain killers, sedatives and anti-biotics to get through the day. The pain has become so great they have decided that now they must act. Can they confront their phobias and sit in a dentist chair for the first time in a decade? Can anything be done for their shocking smiles?

Britain's Worst Teeth follows these four terrifying journeys to the dentist chair. Top dentists will try and save their smiles with root canal treatments, bridges, fillings and veneers. If they have left it too late the only treatment possible will be extraction and dentures. If they can't go through with their treatment at all, it is back to a life of pain and torment.