In English they are called "overdenture" and German "Hybridprothesen".Both terms imply complete dentures that are partially supported by natural teeth.The first term describes the outer covering,while the latter refers to the dual nature of the construction.Both express the essential concept.

    The idea of leaving roots of teeth in the jaw and constructing a complete denture over them is more than 100 years old.The objective was to slow down or prevent the resorption of the residual ridge,which inevitably follows extraction of the teeth.This is still one of the basic concepts today.However,we also know that in addition to the support and retention that can be gained from retained roots,overdentures are actually superior to conventional complete dentures in biting force,chewing efficiency and force discrimination.Proprioception via periodontal receptors plays an important role in neuromuscular function.In cases where there are very few teeth remaining,overdentures are less damaging to the remaining periodontium than are conventional removable partial dentures.