title: Effect of Integration Patterns Around Implant Neck on Stress Distribution in Peri-Implant Bone: A Finite Element Analysis.
abstract: OBJECTIVE
  To investigate the biomechanical performance of different osseointegration patterns between cortical bone and implants using finite element analysis.
  
  
  METHODS
  Fifteen finite element models were constructed of the mandibular fixed prosthesis supported by implants. Masticatory loads (200 N axial, 100 N oblique, 40 N horizontal) were applied. The cortical bone/implant interface was divided equally into four layers: upper, upper-middle, lower-middle, and lower. The bone stress and implant displacement were calculated for 5 degrees of uniform integration (0, 20%, 40%, 60%, and 100%) and 10 integration patterns.
  
  
  RESULTS
  The stress was concentrated in the bone margin and gradually decreased as osseointegration progressed, when the integrated and nonintegrated areas were alternated on the bone-implant surface. Compared with full integration, the integration of only the lower-middle layer or lower half layers significantly decreased von Mises, tensile, and compressive stresses in cortical bone under oblique and horizontal loads, and these patterns did not induce higher stress in the cancellous bone. For the integration of only the upper or upper-middle layer, stress in the cortical and cancellous bones significantly increased and was considerably higher than in the case of nonintegration. In addition, the maximum stress in the cortical bone was sensitive to the quantity of integrated nodes at the bone margin; lower quantity was associated with higher stress. There was no significant difference in the displacement of implants among 15 models.
  
  
  CONCLUSIONS
  Integration patterns of cortical bone significantly affect stress distribution in peri-implant bone. The integration of only the lower-middle or lower half layers helps to increase the load-bearing capacity of peri-implant bone and decrease the risk of overloading, while upper integration may further increase the risk of bone resorption.
authors.affiliation: Key Lab for Biomechanics and Mechanobiology of Education Ministry, School of Biological and Medical Engineering, Beihang University, Beijing, China.
authors.forename: Jingyun
authors.initials: J
authors.lastname: Han
authors.affiliation: Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Yuchun
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Key Lab for Biomechanics and Mechanobiology of Education Ministry, School of Biological and Medical Engineering, Beihang University, Beijing, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
mesh_terms: D001696:Biomechanical Phenomena; D015921:Dental Implants; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D008334:Mandible; D016348:Osseointegration
chemical_list: D015921:Dental Implants
keywords: Dental implant; biomechanics; bone resorption; finite element analysis; osseointegration