title: The evidence for endorsing the use of short dental implants remains inconclusive.
abstract: METHODS
  Medline and Embase databases were searched between 1980 and October 2009 using free text and MeSH terms. Reference lists of retrieved publications were checked.
  
  
  METHODS
  Randomised-controlled trials or prospective cohort studies were eligible that included partially edentulous patients in whom at least five implants (each of length <10mm) were placed and where follow up was >1 year. Main outcomes were estimated failure rate per year and the estimated implant survival rate after two years. Failure was defined as implant removal due to loss of integration, implant mobility, symptoms as pain, neuropathies, paraesthesia, violation of the mandibular canal or psychological reason. Studies designated as 'methodologically unacceptable' were excluded. This was based on the validity assessment described below.
  
  
  METHODS
  One reviewer extracted data from all included trials and another extracted from 25% of them. Validity of included studies was assessed using 'quality assessment of a cohort study' and 'quality assessment of a randomised clinical trial' developed by the Dutch Cochrane Centre. Authors were contacted by email when there were missing data. Sources of heterogeneity were explored using stratified analyses for the determinants surface topography, location (maxilla versus mandible), smoking and bone augmentation procedures.
  
  
  RESULTS
  Twenty-nine studies were eligible including 2611 short implants (lengths 5, 6, 7, 8, 8.5, 9 and 9.5 mm). Twenty-eight were prospective cohort studies and one was a randomised controlled trial. The authors do not present a summary of the quality of the studies. The mean follow up was 3.7 years (range 1.6 - 8.1 years). There was mild to moderate heterogeneity between the studies depending on the length of the implants placed. The estimated survival rate after two years ranged from 93.1% (95% CI: 79.7-100%) for 5mm implants to 98.6% (95% CI: 94.6-100%) for 9.5mm implants.
  
  
  CONCLUSIONS
  There is growing evidence that placement of short (<10mm) implants can be successful in the partially edentulous patient.
authors.affiliation: University of Toronto Faculty of Dentistry, Toronto, Canada.
authors.forename: Asbjorn
authors.initials: A
authors.lastname: Jokstad