A US pharmaceuticals firm has developed a pill that can help halt the progression of gum disease. The treatment uses a novel approach - instead of attacking the bacteria that cause the disease, the drug works by blocking an enzyme that destroys gum tissue. 'This is a whole new concept,' said researcher Sebastian Ciancio. Trials have shown that the pill can arrest periodontal disease in cases so bad that patients have been advised by dentists that they were going to lose their teeth. The treatment was discovered by accident.