임플란트-지대주 나사의 조임과 풀림 시 회전각과 토크의 생역학; 임플란트 종류, 오염과 sandblasting의 효과 = Biomechanics in terms of rotation angles and torques of implant-abutment screw tightening and loosening: Effects of implant types, contamination and sandblasting

다국어 초록 (Multilingual Abstract)

Purpose. The purpose of this study is to analyze the biomechanical differences in rotation angle-torque according to the type of implant and to compare the effects of contamination and sandblasting on the removal torque value (RTV) of abutment screws. Materials and methods. For this study, an automated device for tightening and loosening implant screws was developed, and each 15 implant-abutment complexes of external and internal connection type were prepared, divided into three groups according to the surface treatment of the screw: control group (no treatment), experimental group-1 (artificial saliva contamination and chlorhexidine (CHX) rinsing), and experimental group-2 (artificial saliva contamination, CHX rinsing, and subsequent 50 µm Al2O3 sandblasting). First-RTV was measured for each group, followed by different post-treatment procedures for the screws, and then Second-RTV was measured. During the procedure, the removal torque value and rotation angle vs. time were recorded at a 20 data/s. A standardized protocol was followed for all the tightening and loosening procedures: screw was tightened with 30 Ncm torque and maintained for 5 s, and then rotated in the reverse direction until the torque value reached 0 Ncm. After 10 min of rest period, the screws were loosened to initial point. Results. Statistical analysis of measured data revealed that the internal connection type showed significantly higher First-RTV compared to the external connection type, however, no significant differences in Second-RTV were found. Both experimental groups 1 and 2 showed a decrease in RTVs for both implant types, while the control group showed a decrease in RTV only for the internal type. The internal connection type required a significantly larger rotation angle during the tightening and loosening process. Conclusion. Within the limitations of this study, both artificial saliva contamination and CHX cleansing, as well as sandblasting, decreased RTV in both internal and external connection types. Internal connections were more susceptible to the effects of contaminants.

국문 초록 (Abstract)

목적: 본 연구의 목적은 임플란트 종류에 따른 회전각-토크의 생역학적 차이를 분석하고, 오염과 샌드블라스팅이 지대주 나사 풀림력(RTV)에 미치는 영향을 비교하는 것이다. 재료 및 방법: 자동화된 임플란트 나사 조임과 풀림 장비를 제작하였고, 외부/내부연결형 임플란트-지대주 복합체를 각각 15개 준비하였다. 지대주 나사의 처리 방법에 따라 대조군, 실험군-1(인공타액 오염 후 클로르헥시딘 세척), 실험군-2(인공타액 오염 후 클로르헥시딘 세척과 50 um Al2O3 샌드블라스팅)의 세 군으로 나누었다. 각 군은 First-RTV를 측정한 후에 지대주 나사를 군별로 처리한 후 Second-RTV를 측정하였다. 시간에 따른 풀림 토크와 회전각을 20 데이터/초의 비율로 기록하였다. 조임과 풀림 과정은 나사를 30 Ncm까지 조이고, 5초 유지 후, 역방향 회전시켜 0 Ncm에서 10분의 휴지기를 가진 후 원점으로 복귀하였다. 결과: 자동 계측 값을 통계 처리한 결과 내부연결형이 외부연결형보다 높은 First-RTV 값을 보였으나, Second-RTV의 차이는 없었다. 실험군-1과 실험군-2는 외부/내부연결형 모두 RTV 감소가 있었으나 대조군은 내부연결형에서만 RTV 감소를 보였다. 나사 조임 및 풀림 과정은 내부연결형이 유의하게 더 큰 회전각을 필요로 하였다. 결론: 클로르헥시딘 세척과 샌드블라스팅은 외부/내부연결형 모두에서 RTV를 감소시켰고, 내부연결형에서 감소가 더 크게 일어났다.