Abstract: Objective To study the stress distribution rule on the cervical margin of porcelain -fused -to -metal crown(PFM) under two work conditions when two kinds of materials and two designed margins are adopted. Methods The 3-D finite element method was used to perform the computer analog of the maxillary central incisor, and the stress distribution was analyzed on the cervical margin of PFM crown under two work conditions when two kinds of materials and two different designs were adopted. Results The stress on the cervical margin of PFM crown when the ceramic cervical margin was used was very close to that when the metal cervical margin was used, the stress was much lower than the permissible stress strength of ceramic. 120 degree bevel proved more beneficial for protecting the tooth health. Conclusion Under the normal occlusal force, the cervical margin ceramic of porcelain-fused-to-metal crown is not liable to fracture and can be a choice in clinical practice.

Key words: Stress analysis , Porcelain -fused -to -metal crown , Cervical margin, Shoulder