Aims: The aim of this in-vitro study was to compare the retention force of Polyetheretherketone (PEEK) and Cobalt-Chromium (Co-Cr) clasps by mechanical cycling test simulating ten years of use. Materials and Methods: 72 clasps samples were fabricated on a standardized e-max upper right first premolar. it is divided into 24 Co-Cr clasps. and 48 PEEK clasps which were subdivided into 24... https://www.morehartandweinman.com/product-category/musical-instruments/