In the last 40 years, magnets have been used in dentistry. Initially as anecdotic reports, but recently, after the development of powerful rare earth magnets, new applications of them have arised and offer a clinically proved alternative to mechanical systems. Many experimental and clinical trials have demonstrated their adequate use in prosthetic rehabilitations, partial removable or overdentures, tooth or implant beared, or in other like orthodontics. The authors describe the historical evolution of magnetic systems used in dentistry, their physical and mechanical principles, their attributes as biomaterials and their designs and way of use.