The document discusses the biocompatibility of dental materials. It defines biocompatibility as materials being harmonious with life and not having toxic or injurious effects on biologic functions. Any material used in the body for any period of time as part of a medical treatment is considered a biomaterial. Standards and regulations from organizations like the FDA and ISO have been introduced to ensure the biocompatibility and safety of dental materials. A variety of tests are used to evaluate the biocompatibility of new materials, including primary tests, secondary tests, and usage tests. Chronic exposure to beryllium can cause berylliosis, a serious lung disease, so protective masks and gloves should be worn when working with b