title: Sinking and fit of abutment of locking taper implant system.
abstract: BACKGROUND
  Unlike screw-retention type, fixture-abutment retention in Locking taper connection depends on frictional force so it has possibility of abutment to sink.
  
  
  OBJECTIVE
  In this study, Bicon® Implant System, one of the conical internal connection implant system, was used with applying loading force to the abutments connected to the fixture. Then the amount of sinking was measured.
  
  
  METHODS
  10 Bicon® implant fixtures were used. First, the abutment was connected to the fixture with finger force. Then it was tapped with a mallet for 3 times and loads of 20 kg corresponding to masticatory force using loading application instrument were applied successively. The abutment state, slightly connected to the fixture without pressure was considered as a reference length, and every new abutment length was measured after each load's step was added. The amount of abutment sinking (mm) was gained by subtracting the length of abutment-fixture under each loading condition from reference length.
  
  
  RESULTS
  It was evident, that the amount of abutment sinking in Bicon® Implant System increased as loads were added. When loads of 20 kg were applied more than 5 - 7 times, sinking stopped at 0.45 ± 0.09 mm.
  
  
  CONCLUSIONS
  Even though locking taper connection type implant shows good adaption to occlusal force, it has potential for abutment sinking as loads are given. When locking taper connection type implant is used, satisfactory loads are recommended for precise abutment location.
authors.affiliation: Graduate student, Department of Prosthodontics, College of Dentistry, Chosun University, Gwangju, Korea.
authors.forename: Seung-Jin
authors.initials: SJ
authors.lastname: Moon
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Mee-Kyoung
authors.initials: MK
authors.lastname: Son
authors.forename: Chae-Heon
authors.initials: CH
authors.lastname: Chung