Nanoindentation derived mechanical properties of experimental dental restorative material

The present work examines the mechanical behavior of dental porcelain modified by bioactive glass with a nano/micro-length scale. The samples were fabricated using the sol-gel method. By varying the heat treatment different microstructures were obtained, which were characterized with Raman spectroscopy and scanning electron microscopy, which indicated that increased tempered processing of the dental porcelain favors densification and close porosity. Furthemore, conventional nanoindentation was used to measure the elastic modulus (E) and hardness (n-H). Frequency plots provide evidence of clustering of the bioglass and, hence, the E and n-H data for low- and high temperature processed 58S-modified porcelain vary throughout the sample surface. Finally, Kruskal-Wallis and Mann-Whitney tests reveal significantly higher values of E and n-H for 58S-modified dentalporcelain processed at high temperatures.