임플란트 시스템에 사용되고 있는 torque device의 정확성에 관한 연구

Abstract

The employment of implant screw raised problems such as screw loosening, fatigue fracture and thread wear and those problems lead to failure of implant prostheses eventually. Improper tightening force mainly causes screw loosening which occurs frequently in use of screw. Therefore, properly applied torque for the proper tightening implant screw is needed to prevent screw loosening. Various methods and torque generating devices are developed and employed to apply proper torque clinically. In this study, clinically used torque control devices are measured whether uniformed and precise torque are generated and the differences between each company are also clarified. Digital torque gauge(MGT 12?, Mark-10 Corp., U.S.A.) are employed for measurement and torque driver(3i? Implant Inovations, INC., U.S.A.), torque limiting device(OSSTEM.CO.,LTD., Korea), torque indicating devices(Nobel Biocare™, Nobel Biocare AB, Sweden, Straumann, Institut Strumann AG, Switzerland, Cowell Medi.Co.,Ltd., Korea) are used for torque generating devices. X²distribution was formed for 12 groups in 5 companies and ANOVA was performed to measure torque values generated by each torque generating device. And the followings are resulted. 1. When we Compared with measured mean values of each torque generating devices, OSSTEM 10Ncm and 30Ncm were shown better results on accuracy because they represented small standard errors. Cowell Medi 35Ncm and 25Ncm were shown bad results on accuracy because of large standard errors. 2. As results of examining maximum and minimum of each torque generating devices, Straumann 15Ncm and OSSTEM 10Ncm represented the least standard error on maximum values, and also OSSTEM 10Ncm were the least errors on minimum values. The largest errors were Cowell Medi 25Ncm on maximum values and Cowell Medi 15Ncm on minimum values. 3. Each devices mutually had different settings. Therefore, Comparing type of each devices after standardization, OSSTEM 10Ncm was the most accurate, Cowell Medi 35Ncm was the most inaccurate. 4. The type of passive torque generating devices, such as torque driver type, torque indicating device type, torque limiting device type was not important factors that statistically brought out attended difference. Conclusively, all five companies have been shown slight errors and deviations. This indicates a difficulty of applying precise torque. Therefore, it would be recommended torque generating device should be checked whether uniformed and precise torque can be generated and an error should be corrected.