ABSTRACT
Objective To investigate the effect of different adhesive materials on all-ceramic restoration. Methods The all-ceramic restoration system model of mandibular first molar was established by spiral computed tomography (CT) scanning and computer-aided design (CAD) modeling. Four types of resin adhesive materials (Duo Cement,Lute-It,Rely-X ARC,Variolink II) used in clinics were selected, and the stress distribution was calculated using the ABAQUS software. Results The stress at the bonding interface was the highest when low filler adhesive Lute-It was used. Based on the viscoelasticity analysis, resin adhesives with a larger storage modulus and loss modulus could yield lower stress extremes. Conclusions The study suggests that high-filler type resin adhesives with a large energy storage modulus and loss modulus should be used clinically.
ABSTRACT
Objective To analyze the hemodynamic parameters of Stanford type B aortic dissection based on computational fluid dynamics (CFD), so as to make a thorough evaluation of the disease.Methods Based on CTA images of a patient with complex Stanford type B aortic dissection, the three-dimensional model and hemodynamic numerical simulation were carried out to analyze the velocity distribution of flow field and intersecting fracture profile, as well as the wall shear stress. Results The maximum velocity of blood flow at the entry tear and re-entry tear could reach 1.2 m/s and 2 m/s, respectively, providing references for further evaluation on aortic rupture position and prediction of aortic rupture risk. An obvious low wall shear stress zone was formed on false lumen wall near the entry tear, which was consistent with the thrombus position in the patient. Conclusions CFD could effectively analyze the hemodynamic characteristics of complex aortic dissection, obtain the correlation between aortic dissection and wall shear stress at aorta arch and descending aorta, which contributed to guiding clinical assessment of aortic function for preventing the diseases.