Evaluation of retention values of different telescopic crown attachment materials in implant retained overdenture (an in vitro study)

Statement of problem : A variety of attachment materials were employed to improve stability and retention; nevertheless, some materials show considerable alterations in surface topography upon the application of occlusal stress, which eventually affects denture retention. Recent studies have shown a substantial amount of interest in the usage of metal-free attachment. Purpose: the aim of this study was examining the impact of various telescopic crown attachment materials on implant-retained mandibular overdentures’ retention. Material and Methods : completely edentulous mandibular epoxy models were constructed; wherein various material combinations have been used for constructing telescopic attachments for two implants placed in the canine area. The traditional standardized method was used to fabricate thirty-three identical mandibular overdentures. Based on the material utilized in constructing the secondary coping, the study groups were divided into three categories: PEEK/PEEK, PEEK/ZrO 2 , and PEEK/CoCr. For each research group, primary PEEK copings were created. On a prefabricated abutment, primary copings were cemented in place. In the intended insertion path, secondary copings were positioned over the primary copings and then lifted up into the overdentures’ intaglio surface. In order to