상호 호환성 임프란트에서 지대나사의 풀림에 관한 연구

This study was aimed at evaluating the screw stability between inter changeable abutment and fixture by means of examining the loosening of abutment screw. Diameter 3.8mm thread type of pure titanium fixture in Steri-Oss system was chosen, and it had 0.75mm height of external hexed structure on its top. HL Hexed and HL conical abutment were selected in Steri-Oss, E/P and Gold UCLA abutment were selected in 3i and Estheticone and UCLA abutment were selected in Branemark system. Fixtures were mounted in the epoxy resin block and superstructures were constructed with the above-mentioned abutments. To test screw stability under the condition of loading, implant-superstructure combinations were tightened to the torque of lONcm and the load of 6kgf and l ，000cycles was applied, and then the torque required to loosen the abutment screw was measured with the torque gauge. The obtained results were as follows : 1.The screw stability of Steri-Oss HL Hexed abutment was 1.77±0.15Ncm, and that of HL Conical abutment was 1.83±0.06Ncm. 2.The screw stability of 3i E/P abutment was 2.00 ± 0.17Ncm, and that of 3i Gold UCLA abutment was 2.03 士 0.06Ncm. 3.The screw stability of Branemark Estheticone abutment was 0.73 ±0.15Ncm，and that of Branemark UCLA abutment was 1.73±0.12Ncm. 4.Each screw stability was analyzed by one way ANOVA and compared by sheff test. In result, there was significant difference between Branemark Estheticone abutment and other abutment(P<0.01).