조임 회전력에 따른 치과 임플랜트 지대나사의 응력에 관한 연구
STRESS OF DENIAL IMPLANT ABETMENT SCREW BY THE TIGHTENING TORQUE
이원주, 임주환, 조인호,
소속 상세정보
이원주 ( Lee Won-Joo ) - 단국대학교 치과대학 치과보철학교실
임주환 ( Lim Ju-Hwan ) - 단국대학교 치과대학 치과보철학교실
조인호 ( Cho In-Ho ) - 단국대학교 치과대학 치과보철학교실
KMID : 0362419980360050721
Abstract
Abutment screw loosening of implant restorations is a common problem in the treatment of dental implant. The purpose of this study was to calculate stress and preload from the elongation measurements and to determine maximum tightening torque without plastic deformation of the screw. The length of each gold alloy UCLA screw was measured after tightening to the manufacturer’s recommended torque of 32 N-cm. Similarily, titanium UCLA screws were measured after tightening to the manufacturer’s recommended torque of 20 N-cm. Loosening torque was also measured after tightening to 32 N-cm torque for gold alloy abutment screws and 20 N-cm for titanium abutment screws. The results were as follows ; 1. There was a regressive relationship between screw elongation and tightening torque (gold alloy : r2 = 0.987, titanium : r2 = 0.978), and the mean preload calculated from elongation measurements was 501.11 +/- 26.85 N (gold alloy) and 399.43 +/- 7.61 N (titanium). 2. Stress calculated for the gold alloy and titanium screws at maximum recommended tightening torque was less than 60% of their respective yield strengths and within the elastic range. Maximum tightening torque without plastic deformation was 61 N-cm(gold alloy) and 39 N-cm(titanium). 3. For titanium screws, there was a significant difference between loosening after trial 1 and loosening after trials 2 to 5 (p<0.05). No statistically significant difference was seen in mean loosening torques between the first and subsequent trials for gold alloy screws.
키워드
loosening torgue; preload; screw loosening; stress; tightening torgue; yield strength
원문 및 링크아웃 정보
등재저널 정보