ABSTRACT
AIM: The aim of this study was to assess the mechanical and planning failures of the structural components of tooth-supported and tooth-mucosa-supported removable partial dentures (RPDs). MATERIAL AND METHODS: We evaluated the following components of fifty removable partial dentures: direct retainers (niche, support, retention arm, opposition arm, position on the abutments, type of retainers selected), indirect retainers (position, necessity, and niche), acrylic saddle, major connector, insertion axis and interference of muscles and nerves, which were classified into adequate and inadequate. RESULTS: There was a statistically significant difference between tooth-supported and tooth-mucosa-supported dentures when the major connector was considered. CONCLUSION: The major component failures were the following, in descending order: maintenance of the prosthesis, niche, insertion axis, and acrylic base.