A study of the effect of an anti-rotational inner post screw systems on abutment screw loosening for single implant : Part 1 / 대한치과보철학회지

ABSTRACT

STATEMENT OF PROBLEM: Implant abutment screw joints tend to loosen under clinical conditions. Abutment screw loosening results in loss of preload in function. PURPOSE: Anti-rotational inner post screw (ARIPS) systems were compared with conventional abutment screws to reduce screw loosening. Reverse torque values were evaluated. MATERIAL AND METHODS: 32 implant assemblies (Warentec, Co, Ltd, Seoul, Korea) were organized as the 30-Ncm-torque conventional groups and 30-Ncm-torque ARIPS groups in external and internal system. The specimens were tested to 10(6) cycles at a load of 200N. Preload reverse torque, postload reverse torque, and the ratio of postload reverse torque to preload reverse torque were evaluated. The data were analyzed with unpaired t-test in external and internal systems. RESULTS: In the ratio of postload reverse torque to preload reverse torque, the ARIPS groups showed significant differences than the conventional screw group in both external and internal system. CONCLUSION: Within the limitations of this study, abutment screw loosening was effectively reduced using ARIPS system.