Implant attachments of various designs are used to retain, stabilize and sometimes support overdentures. Tissue supported overdentures stabilized and retained by two to four implants are often the restorations of choice due to patient preference, limitations in finances, insufficient available bone to accommodate a greater number of implants, or needed improvements in esthetics, phonetics and oral hygiene. Female retentive sockets in the overdenture base that snap onto male ball abutments offer such advantages as reduction in hydraulic resistance to coupling, lower functional stress on the implants, retention that can be adjusted downward, easy component replacement and only relatively parallel abutments.