3D FEA Research Of Biomechanical Compatibility Of CDIC Adjustable Taper-Screw Implant

Based on the experience by the researchers of China Dental Implantology Center Ministry of Public Health (CDIC) in summing up the success and failure of clinically applied CDIC? conical dental implant, with optimized design and update surface modification technology, a new type of dental implant — CDIC? adjustable taper-screw implant was brought to birth. This new type of implant consisted of a neck with large diameter and an incorporated thick cylindrical abutment. The improvement of design was to promote the restorative success rate and facilitate the clinical operation. Animal experiment and early clinical application showed the favorable biocompatibility of the implant. By way of computer simulation, this study would use 3-D finite element analysis (3-D FEA) to preliminarily evaluate the biomechanical compatibility of the new type of implant.With the CT scan data of human mandible, configuration information was obtained by eFilm software. The whole process of model construction was: accurate 3-D model of mandible was constructed and assembled with CDIC? adjustable taper-screw implant through Pro/Engineer software. The assembled model was then imported to professional finite element analysis software-ANSYS, which has the connection with CAD soft. Simulating the actual occluding system and applying the approximate loading, 3-D FEA centering on the stress distribution of implant and surrounding bone was carried though. This research would investigate the biomechanical compatibility of CDIC? adjustable taper-screw implant in two sides: 1. the influence of implant length on the stress distribution of implant and surrounding bone; 2. the impact of intruding implant tip into the nasal bottom of cortical bone on the stress distribution of implant and surrounding bone.Results revealed that stress concentration area located at the implant neck toward lingual side and the region of cortical bone contacting with the implant neck. Maximal stress at the former region was between 312MPa-322MPa, and at the later one was at the range of 59MPa- 61MPa. At the implant/bone interface, stressdecreased rapidly from the top of cortical bone to implant root. Stress peak of implant was lower than the fatigue strength of the material. It was also found that implant length had little effect on the stress distribution of the whole structure. At the case of inserting the implant end into the nasal bottom of cortical bone, stress peak was around 300MPa at implant neck, and 49MPa for the cortical bone. Besides, relatively high stress distributed at the tip of implant root. The research indicated that by this method, stress at the implant neck and at the top side of cortical bone decreased effectively, and the stress of the system distributed more uniformly, which was beneficial to the integration of implant and surrounding bone.It was testified by this study that CDIC? adjustable taper-screw implant had preferable biomechanical compatibility, which would not break due to fatigue destruction even under the maximal load of occluding. The stress distribution at the interface of implant and surrounding bone was realistic, which is advantageous to the bone remodeling of mandible. Meanwhile, better stress distribution at the implant/bone interface would be attained when implanting the implant end into the nasal bottom of cortical bone, making the implant more biomechanical compatible, which is of great significance for the instant rehabilitation of CDIC? adjustable taper-screw implant.