In many areas of restorative dentistry, metal-free materials offer an alternative to metal-based restorations while ensuring high levels of biocompatibility and esthetics. Rapidly evolving CAD/CAM technology has significantly expanded the range of materials available, providing access to materials classes and their combinations not previously available within conventional manufacturing, such as zirconia ceramics and hybrid ceramics. Mechanical properties over the decades have changed the clinical long-term success but it is still very much dependent on an appropriate indication and proper material selection These two review article provides an up-to-date overview of the possibilities and limitations of metal-free implant-supported single-tooth restorations.
Resultant treatment concepts are presented and evaluated based on clinical examples. Actually, metal free implant abutments, firstly proposed as alumina ceramics, have been substituted by partially stabilized zirconia; among them can be distinguished prefabricated abutments, cast-on/pressable abutments, and CAD/CAM abutments. Prefabricated abutments are available in various sizes, shapes, and angulations. One-piece ceramic CAD/CAM abutments without an adhesive base are fabricated from monoblocks, like titanium abutments. Today, semi-finished zirconia blanks are the raw material almost exclusively used for this purpose; the interface between the implant and abutment will already have been created during the industrial manufacturing process. The external geometry of the abutment is custom-milled from the blank based on the design data or wax-up. In some cases, a certain amount of modification using, for example, matching sintering ceramics can still be performed.
To summarize, the current solutions are: Hybrid abutment with separate crown part and Hybrid abutment crowns.
For additional informations:
Metal-free implant-supported single-tooth restorations. Part I: Abutment and cemented crowns.
Authors: G. Mergoni, I. Giovannacci, G. Giunta, G. Ghidini, M. Meleti, M. Manfredi, P. Vescovi
An 11-year-old patient was sent to out observation by her pediatrician for a maxillary gingival lesion that had arisen about 2 months earlier and...