Implant Overdenture

magnet and ball groups presented the high¬est incidence of prosthetic complications .
-The most common mechanical problem presented by implant overdentures is the loss in retention, caused by wear, deformation, and fracture of the components of the attachment system over time . A number of studies have reported that changes in the attachment surface lead to the loss of frictional contact through the loosening of the attachment components. Changes in the mechanical properties of the materials used, especially the hardness and elastic modulus, could affect the wear pattern .