title: Implant Vertical Fractures Provoked by Laboratory Procedures: A Finite Element Analysis Inspired from Clinical Cases.
abstract: OBJECTIVE
  To investigate the causes for internal implant fractures, which is suggested to be one of the reasons for marginal bone loss.
  
  
  METHODS
  From a 14-year database of 6051 implants, 10 single implant vertical fractures were identified and the abutments were all castable abutments. The abutments presented contamination and irregularities at the internal connecting areas. The hypothesis was that perfect fit was disturbed by laboratory polishing procedures, and finite element analysis (FEA) using overcorrected and undercorrected castable abutment models were created and tested against a perfect fit model.
  
  
  RESULTS
  The results from the FEA presented that both overcorrected and undercorrected models presented nonuniform excessive plastic strain distribution in the neck portion of the implants where clinically an implant fracture was noted.
  
  
  CONCLUSIONS
  The results suggested that laboratory procedures could induce plastic strain of the implant-abutment complex, which increases the risk of fracture.
authors.affiliation: *Private Practice, Nerimaku-Tokyo, Japan; Adjunct Lecturer, Division of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Tohoku University, Tohoku, Japan. †Doctoral Student, Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden, Private Practice, Milan, Italy. ‡Researcher, Department of Oral and Maxillofacial Surgery and Oral Medicine, Faculty of Odontology, Malmö University, Malmö, Sweden. §Private Practice, Ichinomiya, Aichi, Japan; Institute I.O.R., Tokyo, Japan. ¶Professor and Chair, Division of Oral and Maxillofacial Surgery, Tohoku University Graduate School of Dentistry. ‖Researcher, Dentsply Implants, Mölndal, Sweden. #Associate Professor, Department of Oral and Maxillofacial Surgery and Oral Medicine, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Kenji
authors.initials: K
authors.lastname: Takeshita
authors.forename: Marco
authors.initials: M
authors.lastname: Toia
authors.forename: Yohei
authors.initials: Y
authors.lastname: Jinno
authors.forename: Takashi
authors.initials: T
authors.lastname: Sumi
authors.forename: Tetsu
authors.initials: T
authors.lastname: Takahashi
authors.forename: Anders
authors.initials: A
authors.lastname: Halldin
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
mesh_terms: D000044:Dental Abutments / Q000009:adverse effects; D059605:Dental Implant-Abutment Design; D015921:Dental Implants / Q000009:adverse effects*; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans
chemical_list: D015921:Dental Implants