Channel-shoulder attachments belong to the group known as classical attachments within dental laboratory milling techniques. They are mainly used in the area on and around canines and premolars. These attachments are suitable for disadvantageous pathes of insertion, where telescopic crowns come to their limit and cannot be used successfully.
The attachment parts are:
1. The occlusal shoulder:
This ensures a vertical support and reinforces the attachment against horizontal forces.
2. The attachment itself:
Incorporates the largest friction surface.
3. The channel:
a half-drilling in the proximal area prevents deformation of the attachment through transversal forces.
4. The interlock:
is a drilling in the proximal area or result through the contact of two half channels.
5. The cervical shoulder:
This ensures a vertical support. It can be left out in the case of lingually inclined teeth.