[Fixed prosthetic restorations and the marginal periodontium].

Our considerations are focussed on the problems of "the marginal periodontium and the placement of crown margins". Emphasis has been placed on the scientific basis for the periodontologists' postulation of a supragingival crown margin, the critical evaluation of the indications for subgingival crown margins and the possibilities of correcting unfavorable preprosthodontic situations. The evaluation of the mucogingival environment and the questions of the stability of the selected crown margin/gingiva relations are the subjects of further discussion.