title: Cumulative survival rate of Astra Tech implants: a retrospective analysis.
abstract: OBJECTIVE
  The aim of this study was to analyze the short-term predictability and reliability of Astra Tech implants according to the demographical distribution of patients and condition of implant sites and location of implants.
  
  
  METHODS
  Among patients treated with Astra Tech implant (Astra Tech AB) in the Department of Periodontology at the Dental Hospital of Yonsei University of College of Dentisry and K Dental Clinic from May 2004 to March 2009, 195 implants in 98 patients which had been restored more than 6 months ago were reviewed in this study. Following data were reviewed from patient charts and implants success rate was examined: 1) patient type and implant location, 2) bone status at the implant site, 3) diameter and length of the placed implants, 4) presence or absence of bone augmentation and types of the augmentation.
  
  
  RESULTS
  THE RESULTS FROM THIS STUDY ARE AS FOLLOWS: 1) most implants were placed in the molar area, especially 1st molar area of maxilla, 2) most implants were placed at D2 and D3 bone type, 3) most implants were placed in areas of B and C bone quantity, 4) autogenous and alloplastic bone graft and artificial membrane were used for placement of 74 implants.
  
  
  CONCLUSIONS
  Short-term survival rate of Astra Tech implants was 100%.
authors.affiliation: Department of Periodontology, Research Institute for Periodontal Regeneration, Yonsei University College of Dentistry, Seoul, Korea.
authors.forename: Jung-Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Joo-Yeon
authors.initials: JY
authors.lastname: Sohn
authors.forename: Jung-Chul
authors.initials: JC
authors.lastname: Park
authors.forename: Ui-Won
authors.initials: UW
authors.lastname: Jung
authors.forename: Chang-Sung
authors.initials: CS
authors.lastname: Kim
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: June-Sung
authors.initials: JS
authors.lastname: Shim
authors.forename: Keun-Woo
authors.initials: KW
authors.lastname: Lee
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Choi