Dental fillings have come a long way since mercury amalgams. Mixed into dental composites, Ytterbium Fluoride provides the radio-opacity that allows dentists to identify a filling under X-ray, while due to its high transparency the tooth-like appearance of the filling remains unaffected. Sukgyung AT’s YbF3 series shows the best transparency as well as the highest radio-opacity in the market today, and it is already being used by leaders in the dental composite industry. Various particle sizes are available for optimal application. In addition, SiO2 coating on the surface of YbF3 was designed by Sukgyung AT for silane treatment in order to improve mechanical property of customers’ products.