Finite element analysis to study the effects of using CAD/CAM glass-fiber post system in a severely damaged anterior tooth.

To investigate the stress distribution of a severely damaged maxillary anterior tooth restored with a computer-aided design/computer-aided manufacturing (CAD/CAM) glass-fiber post system. Twelve models were fabricated with different alveolar bone levels and cervical dentin wall thicknesses and studied using a two-dimensional finite element method. A force of 100 N was applied to the lingual surface of the crown at 45 degrees, and the maximum von Mises stress was calculated. A higher stress level was observed in the dentin than in the post and crown. With the reduction of dentin thickness, the maximum von Mises stress in the dentin increased slightly to a peak at a thickness of 1.5 mm, followed by a slight decrease at a thickness of 1.0 mm. However, the relative ratio (RR) values did not show a large difference (RR > 80%). Meanwhile, a large difference in RR values was observed with a change in bone level (RR < 80%). When using a CAD/CAM glass-fiber post system, the maximal von Mises stress was significantly affected by the bone level, rather than by the dentin thickness. Moreover, this system may be applied to the treatment of a maxillary anterior tooth with a bone level of only 2/3.