The American Dental Association (ADA) is a professional organization that represents dentists in the United States. It was founded in 1859 and is the world's largest and oldest national dental association. The ADA works to promote oral health, provide education and resources for dentists, and advocate for the profession. One of its main focuses is on cavity fillers, which are materials used to fill cavities in teeth. The ADA provides guidelines and standards for the use of these materials, ensuring that they are safe and effective.