TiN 코팅된 지대주 나사의 반복 착탈 후 표면 변화와 적합도에 관한 연구

Abstract

The purpose of this study was to evaluate the surface change and fit of TiN-Coated abutment screw in the comparison with titanium alloy and Gold-Tite abutment screw after repeated closing and opening through the examination of tested screws in the field emission scanning electron microscope(FE-SEM;Netherland, Phillips co., model:XL 30 SFEG). Titanium(3i/implant Innovations Inc, USA) and Gold-Tite abutment screws(3i/implant Innovations Inc, USA) were selected and classified into two groups, Group A and C respectively. TiN coated titanium abutment screws were also divided into two groups, Group B and D. The number of the sample in each group was seven. Each sample in each group was composed of one abutment screw, one abutment and one fixture. All fixtures were perpendicularly mounted in liquid unsaturated polyesther with dental surveyor. In order to attach each abutment to implant fixture with abutment screw, the abutment screws of Group A and B were tightened to 20 Ncm, and the those of Group C and D were tightened to 32 Ncm torque using electronic torque controller(Br?nemark system DEA 020 Torque controller) and driver(PHD02N, 3i/implant Innovations Inc, USA). Abutment screws of each group were observed using FE-SEM after thirty times of repeated closing and opening test respectively. After repeated closing and opening test, each abutment was reattached into each fixture by each abutment screw for saturation with polyesther. All samples were cross sectioned with sandpaper and polished. The fit of all samples was observed with FE-SEM. The results were as follows ; 1. In the comparison of Group A and Group B after test, abutment screws of Group A showed more remarkable wear in the threads of the screw than those of Group B. 2. In the comparison of Group C and Group D tightened to 32 Ncm after test, wear of the thread surface of abutment screw was more remarkable in Group C than Group D. 3. There were more severe wear and defect of TiN coating in Group D tightened to 32 Ncm than Group B to 20 Ncm. 4. There was no difference in the fit of abutment screw/fixture/abutment among four groups, Group A, Group B, Group C and Group D. Conclusively, it is suggested that TiN coating of abutment screw be clinically acceptable and be expected to reduce the risk of abutment screw loosening. TiN coating of abutment screw showed good resistance against wear, low friction coefficient and the adequate fit of abutment screw/ implant fixture/ abutment.