Final answer:
The ideal percentage of mercury in dental amalgam is 50% by weight. It is considered safe by the FDA for use in adults and children over six years old, and there has been no established link between amalgams and health problems in clinical studies.
Step-by-step explanation:
The ideal percentage of mercury in amalgam used for dental purposes is approximately 50% by weight. Dental amalgams are a common choice for filling cavities due to their durability, cost-effectiveness, and ease of manipulation. These amalgams are composed of mercury and a mix of other metals, predominantly silver, tin, and copper, and are considered safe by health standards when used as described.
Mercury in amalgams is a topic of discussion due to its toxicity; however, the Food and Drug Administration (FDA) has determined that amalgam-based fillings are safe for both adults and children over the age of six. Even among patients with multiple fillings, mercury levels are well below thresholds associated with harm, and no link between dental amalgams and health problems has been established in clinical studies.
Thus, while amalgams contain a high percentage of mercury, their controlled use within dentistry is seen as safe and effective for treating cavities.