Three-dimensional finite analysis of the application of attachment for restoration of unilateral maxillary defect

PURPOSE: To study the stress of the application of attachment for restoration of unilateral maxillary defect. METHODS: Using the 3-D FE model of the unilateral maxillary defect, two different 3-D FE models of the application of attachment framework for restoration of different unilateral maxillary defects (attachment on the mesial side of the central incisor or canine)were designed and established. RESULTS: The area of stress concentration of the two prostheses were on the palatal base near the position of the anterior teeth . the stress was on the posterior teeth of the healthy side. When the attachment was on the mesial side of the central incisor, the stress of the mesial surface of the central incisor was 1.306MPa,and the stress concentration was at the junction of the attachment and the lingual guide plane. When the attachment was on the mesial of the canine, the stress of the mesial surface of the canine was 0.797MPa, and stress concentration was at the corner of the front and bottom of the lingual guide plane. CONCLUSIONS: The application of attachment for restoration of unilateral maxillary defect meets the biomechanical demands without increasing the stress load on the abutment. And further study of the design of the attachment framework should be done. Supported by Research Fund of Shanghai Municipal Education Commission(Grant No.04BC40) and Shanghai Leading Academic Discipline Project (Grant No.T0202).