A spacer (3) with associated adapter (4) is designed to be fitted on an implant (1). The adapter comprises first and second portions (4b, 4c) designed to cooperate with the spacer and the implant, respectively, for securing the spacer on the implant. The adapter is completely enclosed by the spacer and the implant, and the first portion of the adapter can be designed with slits for forming resilient elements on said portion and/or with penetrating parts which, when the adapter and the spacer are joined together, are deformed as it penetrates into opposite parts in the spacer material. The spacer and the adapter can in this way be easily held together upon application to the implant and can be taken apart when completion work is performed on the spacer.