Your dentist may prescribe antibiotics before dental treatment, known as antibiotic prophylaxis, to safeguard against bacterial infection during procedures with a higher risk factor. Patients with certain medical diagnoses, such as heart disease or joint replacements, may be prescribed antibiotic prophylaxis before treatment to protect against infections being transmitted through the bloodstream, though this is a fairly rare occurrence. However, it is best to eliminate this risk, as failure to do so can result in serious consequences, up to and including death.