title: An in vitro pilot study of abutment stability during loading in new and fatigue-loaded conical dental implants using synchrotron-based radiography.
abstract: OBJECTIVE
  The implant-abutment connection of a two-piece dental implant exhibits complex micromechanical behavior. A microgap is evident at the implant-abutment interface, even in the virgin state, and its width varies when an external mechanical load is applied.
  
  
  METHODS
  This study used high-resolution synchrotron-based radiography in combination with hard x-ray phase-contrast mode to visualize this gap and estimate its size. Commercially available implants with different internal conical implant-abutment connections were imaged. Pairs of implants were imaged as manufactured (new) and after fatigue loading (5 million cycles up to 120 N). Then, different static loads were applied at different angles relative to the implant-abutment assemblies, and the implant-abutment microgaps were measured and compared.
  
  
  RESULTS
  Microgaps existed in all systems. Fatigue loading extended the size of the microgap and increased the possibility of micromovement of the implant-abutment complex. The cone angle of the connection also influenced the stability of the abutment, with flatter cones appearing to be more stable.
  
  
  CONCLUSIONS
  Cyclic loading at medium force (120 N) induces plastic deformation of titanium implants and abutments.
authors: Tatjana
authors: T
authors: Rack
authors: Charité University Medicine, Clinic for Oral and Maxillofacial Surgery, Berlin, Germany.
authors: Tanja
authors: T
authors: Rack
authors: Simon
authors: S
authors: Zabler
authors: Alexander
authors: A
authors: Rack
authors: Heinrich
authors: H
authors: Riesemeier
authors: Katja
authors: K
authors: Nelson
mesh_terms: D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D003799:Dental Stress Analysis / Q000379:methods*; D010865:Pilot Projects; D019252:Radiography, Dental, Digital / Q000379:methods*; D013314:Stress, Mechanical; D017356:Synchrotrons; D014025:Titanium; D016474:Weight-Bearing
chemical_list: D015921:Dental Implants; D014025:Titanium