A finite element analysis of the effect of different margin designs and loading positions on stress concentration in porcelain veneers

الملخص EN

Background : during mastication, stress may concentrate in points in the porcelain veneer which may lead to clinical failure.

This study examined whether different finishing lines and different loading positions affect the bond of the porcelain veneers.

Materials and methods: A 2- dimensional finite element model was made.

Location and magnitude of maximum Von Mises and shear stresses were calculated in porcelain veneer.

Results : stress was concentrated in the butt finishing line more than the deep chamfer and chamfer finishing lines.

Stress was concentrated in the incisal portion more than in the cervical portion of the porcelain veneer.

The incisal loading exerted stress more than the bonding strength of the bonding agent, and more than the cervical and middle third loading.

Conclusion : the best stress distribution was formed around the deep chamfer finishing line.

Clinical failure is inevitable in the butt finishing line and incisal loading.

Incisal edge fracture of the porcelain veneer may be due to deboning of the bonding agent to the enamel and later fracture of the porcelain veneer.