title: Implant stability and bone remodeling up to 84 days of implantation with an initial static strain. An in vivo and theoretical investigation.
abstract: OBJECTIVE
  When implants are inserted, the initial implant stability is dependent on the mechanical stability. To increase the initial stability, it was hypothesized that bone condensation implants will enhance the mechanical stability initially and that the moderately rough surface will further contribute to the secondary stability by enhanced osseointegration. It was further hypothesized that as the healing progresses the difference in removal torque will diminish. In addition, a 3D model was developed to simulate the interfacial shear strength. This was converted to a theoretical removal torque that was compared to the removal torque obtained in vivo.
  
  
  METHODS
  Condensation implants, inducing bone strains of 0.015, were installed into the left tibia of 24 rabbits. Non-condensation implants were installed into the right tibia. All implants had a moderately rough surface. The implants had an implantation time of 7, 28, or 84 days before the removal torque was measured. The interfacial shear strength at different healing time was estimated by the means of finite element method.
  
  
  RESULTS
  At 7 days of healing, the condensation implant had an increased removal torque compared to the non-bone-condensation implant. At 28 and 84 days of healing, there was no difference in removal torque. The simulated interfacial shear strength ratios of bone condensation implants at different implantation time were in line with the in vivo data.
  
  
  CONCLUSIONS
  Moderately rough implants that initially induce bone strain during installation have increased stability during the early healing period. In addition, the finite element method may be used to evaluate differences in interlocking capacity.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden. anders.halldin@mah.se.|DENTSPLY Implants, Mölndal, Sweden. anders.halldin@mah.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Halldin
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Jinno
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Silvia
authors.initials: S
authors.lastname: Galli
authors.affiliation: Department of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Ander
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Jacobsson
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D020878:Device Removal; D020342:Finite Element Analysis; D011817:Rabbits; D033081:Shear Strength; D013499:Surface Properties; D013977:Tibia; D019415:Torque
chemical_list: D015921:Dental Implants
keywords: 
  in vivo
  ; bone condensation; implant stability; remodeling; static strain