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Purpose: This study examined the effects of using four different core-ceramic materials on
the stresses that developed in a single all-ceramic first premolar crown. Materials and
Methods: This was done by analyzing models constructed in an axisymmetric fashion
with finite element analyses. The model had a 600-N vertical load applied uniformly over
a circular area on top of the crown. Particular emphasis was placed on the tensile stresses
that developed. Results: For this particular type of model and loading configuration,
radial tensile stresses were predominant in magnitude. Peak hoop and axial tensile
stresses were approximately 80% and 2% of this value, respectively. The peak radial and
hoop tensile stresses were located on the inside of the coping and scaled with the elastic
modulus of the coping. For the axial component, the peak was located in the veneer
ceramic on its outermost perimeter. Conclusion: Under normal loading, a near-uniform
tensile stress field developed within the coping, directly beneath the contact area. The
magnitude of this stress for realistic bite forces using current design recommendations
was significantly lower than the fracture strength of the four ceramic materials
investigated. The stresses developed within the porcelain were in all instances well below
typical strength values. Int J Prosthodont 2002;15:404-412.
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