Figure 8.
Prediction of the dependence of critical load PR on the cement modulus and thickness for a glass-ceramic (Empress I, Ivoclar-Vivadent, Schaan, Liechtenstein) layer (d = 1.5 mm) cemented to tooth dentin. Calculations are based on Eqs. 4 - 6 (Appendix), assuming the strength of Empress I is 160 MPa and the elastic modulus of tooth dentin is 18 GPa. Two distinctive regions separated by an arrow “A”, which represents the elastic modulus value of tooth dentin Es ≈ 18 GPa, of cement modulus can be identified.