Mechanical Characterisation of Cad/Cam Dental Material and Natural Teeth

Abstract

The aim of this study was to investigate the hardness and the fracture toughness of dental ceramic materials by means of the Vickers indentation technique. One type of most common commercial restorative dental ceramic materials fabricated using CAD/CAM system leucite-based glass-ceramics was selected for study and comparison with laboratory synthetized leucite composites and natural teeth. Obtained results showed that the measurement of hardness and fracture toughness depends on the used conditions (the indenter geometry, the indentation load and the duration of maximal force), morphology of polished surface, type of crack system developed or measured indentations and of course on the empirical equation (Casellas, Shetty et al., Niihara et al., Lankford, Niihara, Laugier, Nakahira) used for calculation of fracture toughness. The results proved that the values of Vickers hardness of our laboratory prepared leucite composites are very close to the values of commercial IPS Empress blocks. The Vickers indentation test was verified as a suitable method for evaluation of fracture toughness of small sized samples of leucite-based dental composites when using low indentation