Removable partial dentures usually have a metal structure that is fixed to the teeth, generally being composed of three principal parts: – The retainers, which link the prostheses to the teeth and which are usually metallic, esthetic or cast, like the attachments. – The connectors, which are the structures that link the different parts of the prosthesis. – The saddle, which holds the artificial teeth. The Kennedy classification is the most widely used to define the types of removable partial dentures according to the teeth that the patient has lost: Class I: bilateral posterior edentulous areas. Class II: unilateral posterior edentulous area. Class III: edentulous area with teeth anterior and posterior to it. Class IV: anterior edentulous area (39).