Purpose: The purpose of this study was to determine the influence of margin design and
taper abutment angle on the stresses developed in all-ceramic first premolar crowns.
Materials and Methods: Four margin designs and three taper abutment angles were
independently incorporated into models examined by finite element analysis. A 600-N
force was applied vertically downward. Results: The taper abutment angle had a
significant influence on the greatest peak tensile maximum principal stresses (11) in the
coping (16.8% change in stress for an 8-degree variation in taper angle). The margin
design had significant influence on the highest peak tensile 11 in the dentin (60%
difference in stress between designs) and lesser significance in the cement (30%). All
calculated values of the highest peak tensile 11 were considerably lower than the
fracture strengths of the respective materials in which the stresses resided. Conclusion: A
smaller taper abutment angle and a larger chamfer radius (equivalent to the modified light
chamfer) are recommended to reduce the magnitude of the greatest peak tensile 11
based on the finite element modeling conducted. Int J Prosthodont 2003;16:442–449.