title: Effects of Screw- and Cement-Retained Implant-Supported Prostheses on Bone: A Nonlinear 3-D Finite Element Analysis.
abstract: OBJECTIVE
  To compare the stresses and displacements on perimplant bone generated by screw- and cement-retained prostheses using the finite element method.
  
  
  METHODS
  Two models were constructed: partial fixed implant-supported prostheses with three elements retained by screws (SFP) or cement (CFP). Vertical and oblique loads of 100 N were applied on the models. Bone was analyzed by the principal stresses σ1 and σ3. The displacement between the implant and the bone was identified by the penetration and gap.
  
  
  RESULTS
  Results showed a similar pattern in the distribution of the principal stresses between both prostheses. Under the σ1 stresses, the SFP showed similar values in the bone compared with the CFP. The analysis of the σ3 showed stress peaks 28% higher in the SFP, considering vertical and oblique loads. Displacement analysis showed a similar pattern and similar values between the prostheses for penetration and gap under both loads.
  
  
  CONCLUSIONS
  There were no important differences in the σ1 analysis and the displacement between the SFP and CFP. The differences in marginal bone level reported between SFP and CFP in some clinical studies may not be related to a mechanical factor.
authors.affiliation: *Adjunct Professor, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. †Graduate, Department of Mechanical Engineering, School of Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. ‡PhD Student, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. §Associate Professor, Department of Restorative Dentistry, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Guilherme Carvalho
authors.initials: GC
authors.lastname: Silva
authors.forename: Guilherme Martins
authors.initials: GM
authors.lastname: de Andrade
authors.forename: Rodrigo Carvalho Pinto
authors.initials: RC
authors.lastname: Coelho
authors.forename: Tulimar Machado
authors.initials: TM
authors.lastname: Cornacchia
authors.forename: Cláudia Silami
authors.initials: CS
authors.lastname: de Magalhães
authors.forename: Allyson Nogueira
authors.initials: AN
authors.lastname: Moreira
mesh_terms: D001732:Bite Force; D001863:Bone Screws; D003738:Dental Cements; D015921:Dental Implants; D003764:Dental Materials / Q000032:analysis*; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D020342:Finite Element Analysis; D006801:Humans; D013314:Stress, Mechanical
chemical_list: D003738:Dental Cements; D015921:Dental Implants; D003764:Dental Materials