Bridges
A bridge is purely parodontal borne tooth replacement for gap closure of an interrupted row of teeth and is fixated to firmly attached bridge anchors at bridge abutments. The chewing forces are exclusively absorbed by the bridge abutments.
Gap closure serves the restoration of chewing function, aesthetics and phonetics as well as the prevention of tooth migration, tilting or elongation of an antagonist in the gap. The interruption of the dental arch through loss of teeth leads to occlusion and articulation difficulties due to the disintegration of contact zones. Tilting of gap restricting teeth, as well as elongation and migration of the antagonists can cause caries and parodontal pockets, avoidable by the prompt integration of a bridge.
A fixed bridge is a functional and aesthetic solution, but often requires filing of healthy adjacent teeth. These teeth holding a bridge construction are called abutment teeth. A bridge abutment is the tooth prepared to hold the bridge anchor. The bridge interlink is located between two bridge anchors.
Bridge types
Single and twin span terminal bridges whose bridge interlinks are located between the abutment teeth are statically favourable. Cantilever constructions require at least two adjacent bridge anchors. Alternatives include removable bridges. One option sparing the tooth's hard substance is the adhesive bridge (also called Maryland bridge).
Cantilever bridges are only borne by bridge abutments on one end. The cantilever part represents a statically unfavourable lever and leads to tilting and loosening of bridge abutments.
The integration of an undivided bridge is only possible if all abutments can be prepared in the same direction of insertion. In the case of tilted abutments, a bridge can only be inserted if it is divided. The connecting link in divided bridges is firmly attached to the bridge anchor at one end. The other end is joined to the bridge anchor by, for example, attachments, dual crowns or screw connections.
The removable bridge is parodontal borne dental replacement indicated for tooth limiting gaps with divided bridge anchors (dual crowns), which can be counted not only as a bridge but also as partial prosthesis. For parodontal-hygienic reasons they are used in large bridges.