Biomechanical Evaluation of Different Implant Positions when Restoring the Maxilla: A Finite Element Analysis

The absence of four upper incisors is a complex and delicate treatment challenge. The fewer implants are placed into the arch is easier to restore esthetically. However biomechanical principles could be jeopardized. This study evaluated the biomechanical behavior on a fixed prosthesis supported by different number and position implants in the anterior maxilla. Four different models, 4 implants supporting four splinted crowns (4l); implants in central incisors as support and lateral incisor as cantilevered elements (CS); one implant in central and one lateral incisors as support, with a pontic and cantilevered crowns (CSLS) and implants in lateral incisors as support and central incisors as pontics (LS) were analyzed by finite element analysis (FEA). The implants received mini conical abutment and zirconia screwed prosthesis. A magnitude force of the 37.5N was applied on each palatal surface of the incisors with 45°angle to the long axis of the implants. The reduction of number of implants increased von Mises stress in all components. Lower values of von Mises stress were observed in the 4I model. In the models with two implants, the CS model showed lower von Mises stress except in framework that is in CSLS model. The study concluded that the number of implants influence in biomechanical behavior and when reduce implant number to enhance esthetically anterior rehabilitation the CS and CSLS models showed better biomechanical behavior.