| BACKGROUND
Laminate veneers have been introduced as a successful and reliable technique for treating malformed, yellow, or chipped teeth.
However, mechanically speaking, their success is questionable. The main reason for the failure of laminate veneer treatments is
their fracture. The present study aims at improving the mechanical features of laminate veneers by investigating the factors
affecting the success of this treatment through a finite element analysis (FEA).
MATERIALS AND METHODS
For assessing the distribution in the laminate veneer of maxillary central incisor under different clinical conditions, first a healthy
natural maxillary central incisor was prepared, and it was scanned by a 3D Scanner. Then, Window finish line design was defined
virtually in the software; feathered incisal edge and overlapped incisal edge were defined virtually. The scanned tooth was
modelled in SOLIDWORKS 2015, and it was then entered into ABAQUS FEA which is an analytical software. Finally, the maximum
stress tolerated in each of these conditions as well as the stress level distribution were recorded and described in different points
of laminate veneers.
RESULTS
The present results showed that in comparison with other preparation designs, Window preparation design creates more tension
in the teeth. Moreover, according to the findings obtained from the finite element analysis, overlapped incisal edge preparation
creates the most tension in porcelain. In all kinds of preparations, the amount of tension imposed on the cement was significantly
less than the tension imposed on teeth and porcelain.
CONCLUSION
It can be concluded that, the preparation, cement thickness, and the angle of the forces applied will significantly change the
maximum internal tension of teeth, porcelain, and the related cement. |