The professional fluoride application (PFA) for controlling dental caries has been used for over 50 years, using products of high fluoride concentrations (9,000 to 54,500 ppm F). In the past, aqueous ...

A century ago, India’s tigers were on the brink of extinction. Slowly, their numbers have rebounded. But that ecological success has prompted a dire problem—and a race to save many of them from ...