title: In vitroretention force measurement for three different attachment systems for implant-retained overdenture.
abstract: OBJECTIVE
  The aim of this study is to compare the retention force of three different types of overdenture attachment systems used in implant-retained mandibular complete overdentures.
  
  
  METHODS
  Twenty-one similar acrylic resin blocks were prepared and divided into three study groups: Group A (snap attachment) - 10 specimens, Group B (locator attachment) - 1 specimen, and Group C (syncone attachment) - 10 specimens. A single rectangular heat cure acrylic resin block with two implant analogs 22 mm apart was used with all specimens. Each specimen was subjected to 5500 cycles of insertion and removal in the presence of artificial saliva, representing 5 years of usage. Retention was measured three times for each specimen using universal testing machine. Data were analyzed using one-way and two-way analysis of variance at 95% level of confidence.
  
  
  RESULTS
  Locator attachment group (Group B) showed the greatest retention level throughout the study, followed by snap attachment (Group A), and syncone attachment (Group C) showed the lowest retention level.
  
  
  CONCLUSIONS
  Regardless of the initial retention level of overdenture attachment, gradual loss of retention values is inevitable. However, the rate of retention loss in overdenture attachments is higher in types which comprised plastic parts within their components, rather than those totally made up of noble metals.
authors.affiliation: Department of Prosthodontics, Menoufia University Hospitals, Shibin al Kawm, Menoufia Governorate, Egypt.
authors.forename: Kareem Mohammed
authors.initials: KM
authors.lastname: Reda
authors.affiliation: Department of Prosthodontics, College of Dentistry, Al Jouf University, Sakakah, Saudi Arabia.
authors.forename: Ibrahim Ramadan
authors.initials: IR
authors.lastname: El-Torky
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Tanta University, Tanta, Gharbia Governorate, Egypt.
authors.forename: Mohamed Nabeel
authors.initials: MN
authors.lastname: El-Gendy
keywords: Fatigue strength; locator; overdenture attachment; retention force; snap; syncone