The present invention relates to a fastening screw having a release preventing groove formed therein, including: a lower fixture (10), which is placed on a gum and serves as an artificial root an abutment (20) with a lower portion coupled to a lower surface of the lower fixture (10) and an upper portion coupled to an artificial tooth and a fastening screw (30) for fastening the lower fixture (10) and the abutment (20) by being coupled with the lower fixture (10) through the abutment (20). The fastening screw (30) includes: a cylindrical head portion (31) having a driver groove (32) formed on an upper surface thereof a body portion (35) formed at a lower portion of the head portion (31) and a threaded portion (34) formed at a lower portion of the body portion (35) and having a thread at an outer circumferential portion of a certain length. The threaded portion (34) is composed of an upper extension portion (34-1) and a lower helical portion (34-2), provided with the release preventing grooves (33, 36) on the outer peripheral surface of the body portion and the outer peripheral surface of the extension portion of the threaded portion (34) respectively. Therefore, according to the present invention, the abutment and the lower fixture coupled by the fastening screw are not easily released by the release preventing grooves formed in the body portion and the threaded portion of the fastening screw, significantly increasing stability of the use for a long period of time.COPYRIGHT KIPO 2017본 발명은 이탈방지홈이 형성된 체결스크류에 관한 것으로, 잇몸에 식립되어 인공치근의 역할을 하는 하부고정체(10)와, 상기 하부고정체(10)에 하면이 결합되되, 상부는 인공치아에 결합되는 어버트먼트(20)와, 상기 어버트먼트(20)를 관통하여 상기 하부고정체(10)와 결합됨으로써 하부고정체(10)와 어버트먼트(20)를 결합하는 체결스크류(30)로 구성되는 이탈방지홈이 형성된 체결스크류에 있어서,상기 체결스크류(30)는 상면에 드라이버홈(32)이 형성된 원기둥형상의 헤드부(31)와, 상기 헤드부(31)의 하부에 형성되는 몸체부(35)와, 상기 몸체부(35)의 하부에 형성되되 일부 길이의 외주연에 나사선이 형성된 나사부(34)로 구성되되, 상기 나사부(34)는 상부의 연장부위(34-1)와 하부의 나선부위(34-2)로 이루어져서, 상기 몸체부의 외주면과 나사부(34)의 연장부위 외주면에는 이탈방지홈(33, 36)이 각각 형성되는 것이 특징인 이탈방지홈이 형성된 체결스크류에 관
