title: Comparative evaluation of the effect of diameter, length and number of implants supporting three-unit fixed partial prostheses on stress distribution in the bone.
abstract: OBJECTIVE
  The purpose of this study was to compare the effects of the diameter, the length and the number of implants on stress distribution in the bone around the implants supporting three-unit fixed partial prostheses in the mandibular posterior edentulism.
  
  
  METHODS
  A mandibular Kennedy II three-dimensional finite element model was constructed. Four fixed partial prostheses with two terminal implant supports of various lengths and diameters, and two fixed partial prostheses with three implant supports of various lengths were designed. In separate load cases, 400 N oblique, 200 N vertical, and 57 N horizontal forces were simulated. The tensile and the compressive stress values in the cortical bone around the collar of the implants and Von Mises stresses in the implants were evaluated.
  
  
  RESULTS
  Although the change in the length of implants did not decrease the stress levels, lower tensile and compressive stress values were observed in the bone for wider implant placement configurations. Similar stress distributions and close stress levels were observed for two wider implant supports in comparison with the three-implant-supported fixed partial prostheses.
  
  
  CONCLUSIONS
  With the use of two implants of 4.1-mm diameter and 10-mm length as terminal supports for three-unit fixed prostheses, the magnitude and the distribution of stresses in the cortical bone around the implant collar is within the normal physiological limits.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Hacettepe University, 06100 Ankara, Turkey.
authors.forename: Haldun
authors.initials: H
authors.lastname: Iplikçioğlu
authors.forename: Kivanç
authors.initials: K
authors.lastname: Akça
mesh_terms: D001641:Bicuspid; D019245:Compressive Strength; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003830:Denture, Partial, Fixed; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000503:physiopathology / Q000534:rehabilitation*; D008334:Mandible / Q000502:physiology; D008963:Molar; D013314:Stress, Mechanical; D013718:Tensile Strength; D016474:Weight-Bearing
chemical_list: D015921:Dental Implants