The Exploration of Primary Stability of Dental Implants in Type IV Jaw Bone
| Autor: | I-Chiang Chou, 周怡江 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 Background: Dental implants have been widely used to restore the occlusal function and esthetics. However, success rates are significant decreased in type IV bone. The implant primary stability is important to implant success, and greatly influenced by the bone quality of recipient site. Purpose: This project was to investigate the factors influencing the implant primary stability in type IV bone and bring up a method that placing the calcium phosphate bone cement in the bottom of implant socket during fixture implantation surgery to increase the implant primary stability in type IV bone. The method was evaluated by three dimensional linearly elastic finite element analysis (3D FEA) and animal study. Materials and methods: The study was divided into 3 parts and included 114 3-D finite element models composed of type IV jaw bone with an implant. Twenty-four models were used to analyze the effects of varied cortical bone thicknesses and implant neck designs on the implant micromotion and stresses before and after osteointegration. Ninety models were for exploring the effects of CPC simultaneously applying in the implant socket with fixture placing on implant micromotion and compressive stress. Furthermore, these 90 models also evaluated the effects of cement distribution in horizontal and vertical directions. Finally, the CPC with dental implants were inserted symmetrically in rabbit bilateral femur. We observed the changes of implant primary stability by resonance frequency analysis and cement distribution by radiographic plain film and Micro-CT. Results: The cortical bone thickness was the major factor to influence the micromotion and stress in type IV bone by the FEA results. The maximum stress and micromotion of the peri-implant bone decreased as cortical bone thickness increased. The micromotion level in full osteointegration was less than that in non-osteointegration. The micromotion could be decreased and the maximal stress were shift from cortical bone to implant body and cement block after the bone cement placing around the implant apical half. In vivo, the placement of CPC with dental implant improved the ISQ level in 5 minutes after implant placing and got high stability after 6 months. The CPC mass was not totally resorbed after 6 months. Conclusions: The cortical bone thickness is the main factor to determine the implant stability in type IV bone. Clinician should measure it before surgery to select a proper implant. Placing the bone cement in the implant apical area could improve the primary stability in FEA and increase the ISQ level in vivo. Since the CPC mass was not totally resorbed after 6 months, further studies are warranted before this technique can be applied in the clinic. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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