[In vitro evaluation of two methods for fractured screw retrieval from dental implants].

The aim of the study was to compare estimated efficiency of fractured dental implant screw removal methods. Twenty screws in implant internal connections were fractured in animal model to test fragment retrieval comparing two methods: using ultrasonic tools (group 1, 10 implants) and special reverse force kit (group 2, 10 implants). Removing screws with ultra-sonic tools proved to be slightly more effective, than using specialized kit. Mean procedure time in group 1 was 4 min more than in group 2. The possibility of screw retrieval correlates with fracture level, as deeper fractured screws were the easiest ones to remove.