Occasionally dentists recommend that certain patients take antibiotics before particular dental procedures. This is called antibiotic prophylaxis. It helps prevent bacteria from entering the blood stream and causing an infection elsewhere in the body. Antibiotics are recommended for a small number of people who have specific heart conditions. These include artificial heart valves, a history of infection of the heart lining or valves, or some heart conditions present from birth. You may also have to take antibiotics before a dental procedure if you have orthopedic implants such as artificial joints. Talk to your dentist if you have any questions about antibiotic prophylaxis.