title: Biomechanical evaluation of a novel porous-structure implant: finite element study.
abstract: OBJECTIVE
  The biomechanical performance of a novel engineered porous-structure implant (EPSI) with various porosities and a conventional solid-structure implant (CSSI) was investigated and compared.
  
  
  METHODS
  The three-dimensional finite element method was applied to titanium dental implant models placed in a block of bone that included both cortical and medullary bone. Five different pore sizes and porosities of the EPSI (58% porosity [PSI-58], 62% porosity [PSI-62], 71% porosity [PSI-71], 75% porosity [PSI-75], and 79% porosity [PSI-79]), were compared with the CSSI. Equivalent von Mises (EQV) stress, strain energy density, and displacement were examined for each implant design.
  
  
  RESULTS
  The maximum EQV stresses exhibited in cortical bone of the EPSI models were lower than those of the CSSI model. Higher EPSI porosity tended to increase the EQV stress. The EPSI appeared to share the load with the cortical bone, as evidenced by lower strain energy density in the cortical bone of EPSI models. High values for displacement were observed at the coronal part of the implant in all models. Slight differences in maximum displacement values were seen between EPSI and CSSI models.
  
  
  CONCLUSIONS
  The EPSI effectively reduced the maximum EQV stress in the cortical bone and enhanced the load-sharing capacity. A significant amount of energy was absorbed by the implant instead of being transferred to the surrounding cortical bone. Varying the porosity of an implant had less effect on implant displacement.
authors.affiliation: Faculty of Dentistry, Thammasat University, Pathumthani, Thailand.
authors.forename: Samroeng
authors.initials: S
authors.lastname: Inglam
authors.forename: Nattapon
authors.initials: N
authors.lastname: Chantarapanich
authors.forename: Siriwan
authors.initials: S
authors.lastname: Suebnukarn
authors.forename: Natapoom
authors.initials: N
authors.lastname: Vatanapatimakul
authors.forename: Sedthawatt
authors.initials: S
authors.lastname: Sucharitpwatskul
authors.forename: Kriskrai
authors.initials: K
authors.lastname: Sitthiseripratip
mesh_terms: D001696:Biomechanical Phenomena; D001842:Bone and Bones; D015921:Dental Implants; D017267:Dental Prosthesis Design / Q000379:methods*; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D003765:Models, Dental; D016062:Porosity; D014025:Titanium
chemical_list: D015921:Dental Implants; D014025:Titanium