- Corals are sea animals that grow in colonies. Corals are most often found in tropical oceans and are known as reef builders because they secrete calcium carbonate to form a hard skeleton.
- Natural and man-made coral are currently being studied for use in bone grafts. Coral has been shown to increase bone strength when incorporated into surrounding bone.
- Although coral may be useful as a bone graft substitute, researchers state that more long-term information on safety and effectiveness is needed. Coral has been associated with an increased rate of infection and may cause problems in those who have or are prone to kidney stones.