A bridge is a fixed dental restoration (a fixed dental prosthesis) used to replace one or more missing teeth by joining an artificial tooth definitively to adjacent teeth or dental implants. Definitions Fixed bridge: A dental prosthesis that is definitively attached to natural teeth and replaces missing teeth. Abutment: The tooth that supports and retains a dental prosthesis. Pontic: The artificial tooth that replaces a missing natural tooth. Retainer: The component attached to the abutment for retention of the prosthesis. Retainers can be major or minor. Unit: Pontics and abutment teeth are referred to as units. The total number of units in a bridge is equal to the number of pontics plus the number of abutment teeth. Saddle: The area on the alveolar ridge which is edentulous where at least one missing tooth is to be reinstated. Connector: Joins the pontic to the retainer or two retainers together. Connectors may be fixed or movable. Span: The length of the alveolar ridge between the natural teeth where the bridge will be placed. Resin bonded bridge: A dental prostheses where the pontic is connected to the surface of natural teeth which are either unprepared or minimally prepared. Advantages and disadvantages of tooth replacement Types of bridge Conventional bridge Conventional bridges are bridges that are supported by full coverage crowns, three-quarter crowns, post-retained crowns, onlays and inlays on the abutment teeth. In these types of bridges, the abutment teeth require preparation and reduction to support the prosthesis. Conventional bridges are named depending on the way the pontic (false teeth) is attached to the retainer. Fixed-fixed bridges A fixed-fixed bridge refers to a pontic which is attached to a retainer at both sides of the space with only one path of insertion. This type of design has a rigid connector at each end which connects the abutment to the pontic. As the abutments are connected together rigidly it is critical that during tooth preparation the proximal surfaces of the abutment teeth must be prepared so that they are parallel to each other. Cantilever A cantilever is a bridge where a pontic is attached to a retainer only at one side. The abutment tooth may be mesial or distal to the pontic. In a spring cantilever, the pontic and retainer are remote from each other and connected by a metal bar. Usually, a missing anterior tooth is replaced and supported by a posterior tooth. This