title: Biomechanical comparison of two different collar structured implants supporting 3-unit fixed partial denture: a 3-D FEM study.
abstract: OBJECTIVE
  The purpose of the study was to compare the effects of two distinct collar geometries of implants on stress distribution in the bone as well as in the fixture-abutment complex, in the framework and in the veneering material of 3-unit fixed partial denture (FPD).
  
  
  METHODS
  The 3-dimensional finite element analysis method was selected to evaluate the stress distribution in the system composed of 3-unit FPD supported by two different dental implant systems with two distinct collar geometries; microthread collar structure (MCS) and non-microthread collar structure (NMCS). In separate load cases, 300 N vertical, 150 N oblique and 60 N horizontal, forces were utilized to simulate the multidirectional chewing forces. Tensile and compressive stress values in the cortical and cancellous bone and von Mises stresses in the fixture-abutment complex, in the framework and veneering material, were simulated as a body and investigated separately.
  
  
  RESULTS
  In the cortical bone lower stress values were found in the MCS model, when compared with NMCS. In the cancellous bone, lower stress values were observed in the NMCS model when compared with MCS. In the implant-abutment complex, highest von Mises stress values were noted in the NMCS model; however, in the framework and veneering material, highest stress values were calculated in MCS model.
  
  
  CONCLUSIONS
  MCS implants when compared with NMCS implants supporting 3-unit FPDs decrease the stress values in the cortical bone and implant-abutment complex. The results of the present study will be evaluated as a base for our ongoing FEA studies focused on stress distribution around the microthread and non-microthread collar geometries with various prosthesis design.
authors: Near East University, Faculty of Dentistry, Department of Prosthodontics, Mersin, Turkey. gokcemeric@yahoo.com
authors: Gökçe
authors: G
authors: Meriç
authors: Erkan
authors: E
authors: Erkmen
authors: Ahmet
authors: A
authors: Kurt
authors: Atilim
authors: A
authors: Eser
authors: Ahmet Utku
authors: AU
authors: Ozden
mesh_terms: D001696:Biomechanical Phenomena; D019245:Compressive Strength; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D003830:Denture, Partial, Fixed; D020342:Finite Element Analysis; D021621:Imaging, Three-Dimensional / Q000379:methods; D013718:Tensile Strength
chemical_list: D015921:Dental Implants