PSI - Issue 79

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

57

Table 2. IPS-Empress and Filtek Z250 fillings properties

Filling

Property

Value

IPS-Empress

Density [g/cm³] 2.4 Compressive ultimate strength [MPa] 280 Young modulus [GPa] 96 Poisson ratio 0.22 Bulk modulus [Pa]

5.7413 E+10

Shear modulus [Pa]

3.9344 E+10

Tensile yield strength [MPa]

70

Compressive yield strength [MPa]

180

Tensile ultimate [MPa]

185

Filtek Z250

Density [g/cm³] 2 Compressive ultimate strength [MPa] 254.31 Young modulus [GPa] 12 Poisson ratio 0.3 Bulk modulus [Pa] 1 E+10 Shear modulus [Pa]

4.61544 E+9

Tensile yield strength [MPa]

88

Compressive yield strength [MPa]

300

Tensile ultimate [MPa]

85

2.4. Loading model The biting force of 453 N was applied obliquely at a 45-degree angle to the long axis of the tooth. This approach simulates the stress state of the tooth during occlusion, utilizing the stress distribution normal to the oblique surface [7, 24]. Consequently, the driving force that extends the crack is predominant, as illustrated in Fig. 3. The maximum stress concentration is identified.