Determination of Elemental Composition of Substance Lost Following Wear of All-Ceramic Materials

Purpose: The aim of this study was to test the possible elemental release of four different all-ceramic materials in a wear machine to predict results about their long-term behavior in the oral environment. Materials and Methods: Four different all-ceramic materials with different chemical compositions were selected for the wear testing. A total of 20 cylindric samples, five for each ceramic group, were prepared according to the manufacturers¡¯ instructions. These were subjected to two-body wear testing in an artificial saliva medium under a covered unit with a computer-operated wear machine. The artificial saliva solutions for each material were analyzed for the determination of amounts of sodium, potassium, calcium, magnesium, and lithium elements released from the glass-ceramic materials. The differences between and within groups were statistically analyzed with a one-way ANOVA, followed by Duncan tests. Results: The statistical analyses revealed no significant differences among Na, K, Ca, or Mg levels (P >= .05) released from the leucitereinforced groups, while there was a significant (P .05) increase in Li release from the lithium disilicate group. Conclusion: Considerable element release to the artifical saliva medium was demonstrated in short-term wear testing. The lithia-based ceramic was more prone to Li release when compared with other elements and materials.