Implant-supported removable overdentures in the edentulous maxilla: Clinical and technical aspects

Purpose: The aim of this article is to describe the indication criteria and the treatment planning for a maxillary implant-supported removable overden ture. Prostheses are designed according to the requirements of the bar syst em and the factors influencing the extension of the prosthesis base. Materi als and Methods: The decisive factors in determining whether a bar-retained overdenture prosthesis is indicated should be evaluated during the initial clinical examination and with the help of a reformatted computed tomograph ic (CT) scan that is performed with a radiologic template in place. Titaniu m markers represent the ideal location of the denture teeth in the diagnost ic setup so that the implant position can be selected and the available spa ce for the bar system can be assessed Vertically and horizontally. Results: For the overdenture prosthesis that is solely implant supported 6 to 8 imp lants are placed ideally at a distance of about 10 to 14 mm from center to center. A prefabricated bar system that allows the clips to be inserted bet ween the implants can then be used. When the available bone restricts impla nt placement to adjacent tooth positions an individually milled bar that in cludes additional frictional pins and/or retentive elements needs to be pla nned. The prosthesis design, in particular its buccal and palatal flange ex tension, is determined during setup try-in, taking into account the patient 's smile line, their need for facial support, and their phonetic requiremen ts. Conclusion: The removable implant-supported overdenture offers flexibil ity in placing implants in either adjacent tooth positions or with greater distances between them depending on the available bone, as either conventio nal bar and clip systems or individually milled bars can be used. Adjustmen t of the buccal prosthesis flange and the palatal prosthesis base is made t o fulfill the patient's requirements concerning esthetics, phonetics, comfo rt, and function.