H. H. Renggli

Axial strengths of foil, all-ceramic and PFM molar crowns

Abstract The axial strength of crowns on master dies, made of 3 foil systems (Flexobond; Plati-deck; Ceplatec), has been evaluated. A conventional porcelain-fused-to-metal (PFM) crown, a castable ceramic system (Dicor) as well as an injection molded all-ceramic crown system (Cerestore) were used as a reference. The PFM crowns turn out to have significantly higher failure loads. Cerestore and Flexobond have corrected failure loads which are approximately 60% of the PFM fracture load. Ceplatec follows at approximately 40% of the PFM fracture load, while the fracture loads of Plati-deck and Dicor turn out to be approximately 30% of the PFM value. Plati-deck can be improved by a better metal/porcelain bond. Similarly, but to a lesser extent, it might be possible to improve Ceplatec (Renaissance) and Flexobond. The Dicor strength was restricted by the presence of gross porosities present at the inner side of the crown.

Electroformed gold dental crowns and bridges

Continually spiralling costs of dental treatment have encouraged ongoing research into both alternative materials and more efficient processes. One such process finding increasing use in industry is electroforming and recent work in gold electroforming encourages the hope that this technique may find application in dental treatment.