Telescope retainers for removable partial dentures.

Telescope crowns used in removable partial dentures reduce the destructive horizontal and rotational occlusal forces by directing them more axially and less traumatically than other retainers. These properties are combined with excellent conditions for cross-arch and multiple abutment splinting. If one of the abutment teeth needs extracting, the denture can be repaired with acrylic resin simply by remaking the secondary crown into a pontic. The single copings can be easily cleaned due to the good accessibility around their gingival margins. They also protect the abutment teeth against caries and thermal irritation. Soldering of the primary copings or their connection with accessory bars is not necessary in rigidly constructed telescope crowns, because the secondary crowns incorporated in the superstructure provide sufficient rigidity. In addition, the splinted copings often cause inflammatory gingival hyperplasia because the solder joints are too close to the gingival margins, preventing proper hygiene maintenance. The taper configuration or vertical height of the coping, which determines the amount of load transferred to each abutment, can be planned to suit each tooth's condition and designated function in the restoration. In a fixed restoration, the load is always evenly distributed among all the abutment teeth regardless of their condition, because the crowns are permanently cemented to them. In the telescope denture, the amount of force can be individually regulated by modifying the form and leverage of the retainers, according to their position, bone support, and occlusal conditions.