Design and analysis of tooth abutment implant

Abstract

In human being, tooth loss is a common problem which may be due to various disease and trauma. Dental implants are used to provide support for the replacement of missing teeth. Research on dental implant designs, materials, and techniques is continuously increasing. There is still a lot of work involved in the use of better biomaterials, implant design, surface modification, and functionalization of surfaces to improve the long-term benefits of implant treatment. This paper provides a brief history of dental implants and its parts. This describes the new designs and conventional design of tooth abutment implant and stress distribution using finite element analysis method on the surface of the whole system under various loading conditions. It describes the suitable materials and its properties which can be used for making tooth abutment implant. This also describes how to remove complexities which is associated with tooth abutment implants such as its motion, complex design of screw, and high cost. Background: The attempts to overcome the problem of tooth loss and to find out a way of replacing missing teeth date back to as old as the history of human beings. Many materials, many geometric forms, surgical and prosthetic methods have been tried till now for the dental implants. Scarcely existing archeological reports demonstrate the attempts of different prosthetic devices used as natural and functional replacements. It is found that transplantation procedures and devices are used by Egyptians, Greeks, Romans, Chinese, Indians and Arabs. Furthermore naive artificial units such as shaped stone, wood, cast iron and carved sea shells, bone and natural teeth taken from various animals and even teeth sold by the poor or slaves have been tried as implantation material. A tooth shaped piece of shell is found by an archeologists which is placed into the socket of missing teeth of a women in 1931. Later, in 1970, a Brazilian dental academic, Amadeo Bobbio, investigated that mandibular specimen and in the radiographs he took, he observed bone formation around the implant-like structures. In 18th century, humans donated their teeth in exchange for some fee but human's body precluded the adaptation of foreign materials. Le Mayeur implanted one hundred and seventy donated teeth in 1785 and 1786 but he was not able to get successful results. In 19th century, predicating on a false assumption that precious materials would be well tolerated by biological tissues, gold, silver, platinum and some other metal alloys were used as implant materials, which resulted in extremely poor long-term results. The human's body reject these type of material basically because they were not inert. Venable et al. (1937) found that the metals that are not inert they tend to ionize when they come into contact with body resulting in producing metallic salts causing excessive proliferation of some tissues whereas inhibiting bone formation. The prevention of bone formation around the implant leads to failure of the implantation. The modern breakthroughs in dental implantology emerged as a result of so-called serendipity of a Swedish orthopedic surgeon, Dr. Branemark, in 1952. While studying bone healing and regeneration around 'the rabbit ear chamber', which was a chamber of titanium designed and developed as a part of research conducted in Cambridge University, he observed in microscopic level that bone had grown around titanium surface in so close proximity that he was unable remove the chamber form the rabbit femur. Dr. Branemark investigated this phenomenon through further studies on animal and volunteer human tissues, which all contributed to unveiling the biocompatible properties of titanium. Having initially been considered to be appropriate for applications in the field of orthopedics such as knee or hip surgery, later titanium is realized to be utilized as anchorage for dental prosthesis and artificial crowns. The first titanium implant was inserted into the jawbone of a human volunteer, Gosta Larsson, for providing an artificial root for prosthetic teeth. Also, in 1967, Leonard Linkow presented his blade-form titanium implants providing mechanical stability and function for partial and complete dentures. In 1970 to 1980 many experimental studies were carried out to obtain better designs and geometric forms for titanium dental implants some of which are the IMZ Implants, TPS Implants, ITI Hollow-Cylinder Implants. Throughout this period, Dr. Branemark continued his research and in 1971 he introduced titanium hollow screw implants which resulted in increased success rate, clinical applicability and reduced rate of complications compared to blade-form implants. In 1978, he established a commercial partnership with a Swedish defense company, Bofors AB. In 1981, based on the partnership, Nobel Biocare, one of the largest current dental implant producers in the world, was founded with the aim of focusing directly on dental implantology. In the year 1982, the Toronto Conference on osseointegration in Clinical Dentistry set the first guidelines for successful implant dentistry. The successful integration of hollow screw geometry into bone and high biocompatible characteristics of titanium resulted in that screw form dental implants have become the preferred method of tooth replacement and a standard dental treatment technique. Providing a high rate of success and a wide range of restorative options, today, dental implants, under various brand names, are extensively used worldwide. Current studies are mainly focused on improving aesthetics, reducing healing period and simplifying the use of dental implants. Objectives: Based on the previous work it was observed that the current dental implant suffers from several shortcomings. In order to minimize these shortcomings several objectives are as follows-. 1. Make a novel design of tooth abutment implant without using screw because the manufacturing process of screw of small part is difficult and costly. 2. Model the new improved tooth abutment implant and subject it to working load. 3. Model the implant considering cost minimization of tooth abutment implant. 4. Analyze and validate the results of stress analysis. Materials and Methods: Here Titanium alloy is used for making new designs because it has better biocompatibility, bonding strength, high corrosion resistance and it prevents to fracture. Solidworks software is used for modeling and ANSYS software is used for analysis. Results: Von-Mises stress distribution is calculated under normal load and maximum load on the top surface of the abutment of conventional design and new designs. Conclusions: After comparing the stress distribution of all the new designs with conventional design and ultimate strength of titanium alloy found the best design of tooth abutment implant.