Mechanism of the dentino-enamel junction on the resist-crack propagation of human teeth by the finite element method

OBJECTIVE: This study aims to identify the crack tip stress intensity factor of the propagation process, crack propagation path, and the changes in the shape of the crack tip by the finite element method.

METHODS: The finite element model of dentino-enamel junction was established with ANSYS software, and the length of the initial crack in the single edge was set to 0.1 mm. The lower end of the sample was fixed. The tensile load of 1 MPa with frequency of 5 Hz was applied to the upper end. The stress intensity factor, deflection angle, and changes in the shape of the crack tip in the crack propagation were calculated by ANSYS.

RESULTS: The stress intensity factor suddenly and continuously decreased in dentino-enamel junction as the crack extended. A large skewed angle appeared, and the stress on crack tip was reduced.

CONCLUSION: The dentino-enamel junction on human teeth may resist crack propagation through stress reduction.