Patient selection and preparation should take place lege artis. The selection and prognosis of suitable abutment teeth is as for conventional procedures.
Any tooth which requires a crown can benefit from a long-term restoration in the form of an electro-formed crown. This statement is made on the assumption that the practitioner exercises the required care during the preparation and impression-taking as well as during insertion of the restoration. In order to receive an electroformed crown, the prepared tooth must be prepared as smooth as possible, without grooves or other irregularities, and have a well defined preparation is a chamfer or shoulder with rounded inner edge- a tangential preparation is contra-indicated here.
Important:
The occlusal, lingual or palatal reduction of the hard tooth substance must be 1.2-1.4 mm in order to achieve a ceramic layer with a depth of 1-1.2 mm.
In the case of abutment of tooth and inlay preparations, the die must be built up and filled as part of the preparation process. Subsequent blocking out performed on the model or by using cement should be avoided.
Because of the accuracy of the AGC electroforming process, the impression must be taken with particular care. This applies equally to the crown, anchor crowns, inlays and three-quarter crowns.
Important:
The impression should give an accurate reproduction of the exact preparation margin and an area apical to the preparation margin, so that it can later be transferred to the situation on the model.
It is not recommended to carry out a temporary cementation of electroformed crowns, bridges or inlays.
In the case of epigingival and sub gingival preparation margins, it is particularly difficult to transfer the situation in the mouth to that on the model. If the patient shows a good state of periodontal health, then the preparation margin can be reproduced accurately lege artis by using method of gingival retraction.
The established zinc phosphate cements are best suited for permanent cementation. However, modern glass ionomer cements as well as composite cements can also be used. As a result of the excellent fit of the electroformed substructures, it is sufficient to apply a thin coat of cement to the inner surface of the restoration using a brush (see photos).
