title: Systematic review of outcome measurements and reference group(s) to evaluate and compare implant success and failure.
abstract: BACKGROUND
  There is a lack of consensus on measures to assess implant performance in clinical research.
  
  
  OBJECTIVE
  To investigate the outcomes measures and reference groups employed to evaluate and compare implant success and failure.
  
  
  METHODS
  MEDLINE (OVID) and Web of Science with searching reference lists of included papers.
  
  
  METHODS
  Inclusion: root form, titanium implants in dentate or edentulous individuals. Longitudinal studies reporting survival or success outcomes on at least 20 participants ≥ mean 5 years.
  
  
  METHODS
  Descriptive statistics.
  
  
  RESULTS
  Two-hundred and sixteen studies were included. Implant survival was the most commonly reported primary outcome (60%) with success at 15.7%. Success constituted a wide variety of measures with little consistency. A percentage of 98.6% of studies employed the implant as the unit of analysis with little consideration of clustering within patients. The status of periodontal and general heath of study groups was unclear for more than 80% studies. The proportion of studies comprising randomized trials or using appropriate analytical methods increased from 1980 to 2011.
  
  
  CONCLUSIONS
  Considers only English language and there was no author contact.
  
  
  CONCLUSIONS
  In view of the disparate outcome measures employed to assess dental implant performance, agreement is needed both on a core set of implant outcomes and their statistical management.
authors.affiliation: Unit of Periodontology and International Centre for Evidence-Based Oral Health, UCL Eastman Dental Institute, London, UK. i.needleman@ucl.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Needleman
authors.forename: Sarah
authors.initials: S
authors.lastname: Chin
authors.forename: Tim
authors.initials: T
authors.lastname: O'Brien
authors.forename: Aviva
authors.initials: A
authors.lastname: Petrie
authors.forename: Nikos
authors.initials: N
authors.lastname: Donos
mesh_terms: D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D019232:Dental Restoration Failure; D006801:Humans; D008137:Longitudinal Studies; D016032:Randomized Controlled Trials as Topic / Q000592:standards; D012107:Research Design / Q000592:standards*; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants