PSI - Issue 79

Mays H. Udah et al. / Procedia Structural Integrity 79 (2026) 53–64

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Fig. 5. FEM crack propagation using ANSYS, F=453 N

To investigate the impact of these differences on fracture development and growth in the tooth, the program was executed under two cases of dentin properties: one with minimum values and the other with maximum values. Analysis of these two cases revealed that the maximum anisotropic tooth requires approximately 100 N more force than the minimum anisotropic tooth to reach the crack growth stage, as shown in Fig. 6.

(a)

(b)

Fig. 6. Principle stresses of dentin: (a, and b) maximum and minimum values of dentin properties, respectively.

ANSYS program was run using the properties of these two fillings to verify the performance of these fillings, once for filling Filtek Z250 and another time for filling IPS-Empress, and in two cases of the shape of the cavity in the place of the filling in the tooth, which are square filler shape and round filler shape, to study the effect of the cavity shape on the development of the fracture and to compare the performance of two fillings. The results of the ANSYS program for the two fillings, Filtek Z250 and IPS-Empress, and the two cases, round and square, are shown in Figs 7 and 8. These results for the filling IPS-Empress showed the emergence of the fracture starting point at the bottom of the upper surface of the tooth and the middle.