[Perioprosthetics are one of the most sensitive fields of dentistry].

The success of a prosthesis, in the past was related only to the perfectness of construction and the occlusion. Nowadays the criterion for the acceptance of a prosthesis is its good relation to the gingival tissues. It would be a great error to isolate some parts of the prosthesis and study their possible influence to the gingival tissues. Instead of this, prosthesis should be seen on its whole. The proceeding for the prevention of the periodontal damage is related to all the stages of the construction of a prosthesis beginning from the tooth preparation, the impression till the fixation of the temporary prosthesis. According to these, the present study deals with the elements of the prosthesis which may affect the gingival tissues.