title: Abutment screw loosening of endosseous dental implant body/abutment joint by cyclic torsional loading test at the initial stage.
abstract: Cyclic torsional loading tests were carried out in the laboratory using various implant systems, in order to clarify differences between the systems in loosening of abutment screws. Six samples from six commercially available abutment systems were used, giving a total of 36 samples. Four of the systems used internal connections, and two used external connections. The abutment screw for each system was tightened to a torque value specified by the manufacturer, and after 5 min, the loosening torque was measured using a digital torque meter. Measurements were taken twice, and a second measurement was taken as a reference value. A cyclic torsional loading test with 100,000 cycles was performed on the sample, and the loosening torque was again measured after the test. In conclusion, loosening of the abutment screw occurred as a result of cyclic torsional loading, and the degree of loosening varied with each implant system.
authors.affiliation: Department of Crown and Bridge Prosthodontics, The Nippon Dental University, School of Life Dentistry at Niigata.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Katsuta
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Watanabe
mesh_terms: D001863:Bone Screws; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D020878:Device Removal; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D019415:Torque
chemical_list: D015921:Dental Implants