ABSTRACT
<p><b>OBJECTIVE</b>To investigate the stress distributions under load in an all-ceramic crown of the upper central incisor in differential thickness.</p><p><b>METHODS</b>The 3-dimensional finite element model of all-ceramic crown of the upper central incisor in differential thickness was applied with differential loads (100, 150, 200 N). The stress values and distributions of all-ceramic crown were calculated and expressed.</p><p><b>RESULTS</b>The tendency of stress distributions in all-ceramic crown of differential thickness and loads was similar. The maximal stress intensity value was located in the loading site and the cervical region. As the thickness of all-ceramic crown increased, the stress concentration reduced. When the load increased, the stress values increased, especially in the loading site and the cervical region.</p><p><b>CONCLUSION</b>The increasing of the thickness of all-ceramic crown will decrease stress concentration. Because stress concentration is mainly in cervical region and loading site, these regions should be cared in fabrication of all-ceramic crown.</p>