Clinical Translational Research Center for Dental Science, Seoul National University Dental Hospital, Seoul, Republic of Korea.
Department of Oral and Maxillofacial Surgery, School of Dentistry, Seoul National University, Seoul, Republic of Korea.
J Healthc Eng. 2017;2017:4842072. doi: 10.1155/2017/4842072. Epub 2017 Aug 6.
The prosthetic component of dental implant is attached on the abutment which is connected to the fixture with an abutment screw. The abutment screw fracture is not frequent; however, the retrieval of the fractured screw is not easy, and it poses complications. A retrieval kit was developed which utilizes screw removal drills to make a hole on the fractured screw that provides an engaging drill to unscrew it. To minimize this process, the abutment screw is modified with a prefabricated access hole for easy retrieval. This study aimed to introduce this modified design of the abutment screw, the concept of easy retrieval, and to compare the mechanical strengths of the conventional and hollow abutment screws by finite element analysis (FEA) and mechanical test. In the FEA results, both types of abutment screws showed similar stress distribution in the single artificial tooth system. A maximum load difference of about 2% occurred in the vertical load by a mechanical test. This study showed that the hollow abutment screw may be an alternative to the conventional abutment screws because this is designed for easy retrieval and that both abutment screws showed no significant difference in the mechanical tests and in the FEA.
牙种植体的修复部件附着在与固定器相连的基台上，基台通过基台螺丝固定。基台螺丝断裂并不常见，但取出断裂的螺丝并不容易，而且会带来并发症。我们开发了一种取出套件，该套件利用螺丝取出钻头在断裂的螺丝上打孔，提供一个可拧开螺丝的钻头。为了最小化这个过程，对基台螺丝进行了改进，增加了预制的进入孔，以便于取出。本研究旨在介绍这种改良的基台螺丝设计、易于取出的概念，并通过有限元分析（FEA）和机械测试比较传统和空心基台螺丝的机械强度。在 FEA 结果中，两种类型的基台螺丝在单个人工牙系统中显示出相似的应力分布。机械测试中垂直载荷的最大负载差异约为 2%。本研究表明，空心基台螺丝可能是传统基台螺丝的替代品，因为它是专门为易于取出设计的，而且两种基台螺丝在机械测试和 FEA 中都没有明显差异。
