title: Strains Around Abutment Teeth with Different Attachments Used for Implant-Assisted Distal Extension Partial Overdentures: An In Vitro Study.
abstract: OBJECTIVE
  The aim of this study was to evaluate and compare strain around abutment teeth with different attachments used for implant-assisted distal extension partial overdentures (IADEPODs).
  
  
  METHODS
  A mandibular Kennedy class I acrylic model (remaining teeth from first premolar to first premolar) was constructed. A conventional partial denture was constructed over the model (control, group 1). Two laboratory implants were then placed bilaterally in the first molar areas parallel to each other and perpendicular to the residual ridge. Three additional experimental partial overdentures (PODs) were constructed and connected to the implants using ball (group 2), magnetic (group 3), and Locator (group 4) attachments. Three linear strain gauges were bonded buccal, lingual, and distal to the first premolar abutment tooth at the right (loading) and the left (nonloading) sides. For each group, a universal testing device was used to apply a unilateral vertical static load (50 N) on the first molar area, and the strain was recorded using a multichannel digital strainometer.
  
  
  RESULTS
  Significant differences between groups and between sites of strain gauges were detected. Strains recorded for all groups were compressive (negative) in nature. Group 1 demonstrated the highest strain, followed by group 3 and group 4; group 2 recorded the lowest strain. For group 2, the highest strain was recoded at the lingual nonloading side. For group 1, group 3, and group 4, the highest strain was recorded at the buccal loading side.
  
  
  CONCLUSIONS
  Within the limitation of the present study, ball attachments used to retain IADEPODs to the implants were associated with lower strains around abutment teeth than Locator and magnetic attachments. The highest strain was recorded with conventional partial dentures.
authors.affiliation: Department of Removable Prosthodontics, Faculty of Dentistry, University of Mansoura, Eldakahlia, Egypt.
authors.forename: Moustafa Abdou
authors.initials: MA
authors.lastname: ELsyad
authors.affiliation: Faculty of Dentistry, University of Mansoura, Eldakahlia, Egypt.
authors.forename: Abdelbaset Omar
authors.initials: AO
authors.lastname: Omran
authors.affiliation: Department of Removable Prosthodontics, Faculty of Dentistry, University of Mansoura, Eldakahlia, Egypt.
authors.forename: Mohammed Mohammed
authors.initials: MM
authors.lastname: Fouad
mesh_terms: D000044:Dental Abutments; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D003828:Denture, Overlay; D006801:Humans; D003765:Models, Dental
chemical_list: D015921:Dental Implants
keywords: Strain; abutment; attachments; distal extension RPD; implant