There are thousands of different types of precision attachments used in dentistry. However they have not been widely used in the UK.
A precision attachment is a hidden male and female type of clip hidden under a denture or prosthesis and attached to crowns or implants. They are all designed to enable dentures/prostheses to be clipped into place so that they do not move until they are unclipped. They are usually not visible when everything is in its place in the mouth. They can be used to replace visible silver or gold clasps (clips) on conventional dentures in many situations.
The design varies enormously from a bar on two or more implants or teeth with a rider clip(s) in the denture to male and female slots and grooves in crowns. Rubber O-ring retainers on a ball in a tooth or implant are another example commonly used. Some are intracoronal (fit inside a crown) and some are extracoronal ( are attached to the outside of the crown). It is a vast field technically.
John Grummitt has been using many types of precision attachments throughout his over thirty year career. He is always happy to discuss how they may be of help in any situation where hidden denture or prosthesis retention is required.