title: Factors influencing primary dental implant stability remain unclear.
abstract: METHODS
  During a 10-year period, 316 patients had 1084 Branemark implants placed at the same clinic. The mean age was 50.70 ± 12.31 years, with 55% of the study population female and 45% male.
  
  
  METHODS
  A number of exposure variables were evaluated in multivariate analyses including age, gender, smoking habit, periodontal status, implant dimension (length and diameter), and implant location.
  
  
  METHODS
  Implant stability--the ability to withstand loading in axial, lateral, and rotational directions--was determined by using a Periotest device (Medizintechnik Gulden, Modautal, Germany). A Periotest value (PTV) cut-point of -2 was used.
  
  
  RESULTS
  The site of implant insertion showed the strongest association with failure of primary dental implant stability. Implants in the anterior mandible had a 6.43-fold lower risk of primary implant stability failure versus other sites. The maxilla had a 2.7-fold higher risk of primary stability failure versus the mandible. Females had a 1.54 higher risk of primary implant stability failure versus men, and implants less than 15 mm in length had a 1.49fold higher risk of primary implant stability failure versus longer implants.
  
  
  CONCLUSIONS
  According to this study, failure to achieve primary stability as quantified using the Periotest value (PTV) is more likely in females, at sites other than the anterior mandible, and with implants less than 15 mm in length when using machined surface implants.
authors.affiliation: Prosthodontics and Dental Research, UNC School of Dentistry, 330 Brauer Hall, Chapel Hill, NC 27599, USA. Lyndon_cooper@dentistry.unc.edu
authors.forename: Lyndon F
authors.initials: LF
authors.lastname: Cooper