Fracture strength of all-ceramic crowns with varying core elastic moduli

The aim of this study was to investigate the fracture strength of aluminous porcelain jacket crowns on core structures with different elastic moduli. Forty standardized aluminous porcelain jacket crowns were fabricated and divided into four groups. Each crown was luted with zinc phosphate cement onto a master die with a known elastic modulus, and loaded until failure occurred. The fracture load was shown to increase with increasing elastic modulus of the core. Analysis of data by ANOVA revealed a significant difference (p < 0.05) between the four groups. The results suggested that core elastic modulus may have an influence on the fracture resistance of aluminous porcelain jacket crowns, and it may be appropriate to recommend the use of high modulus metals for core placement on teeth to be restored with all-ceramic crowns.