title: Quality of reporting of randomized clinical trials in implant dentistry. A systematic review on critical aspects in design, outcome assessment and clinical relevance.
abstract: BACKGROUND
  The aim of this systematic review (SR) was to assess the quality of reporting randomized clinical trials (RCTs) in the field of implant dentistry, its evolution over time and the possible relations between quality items and reported outcomes.
  
  
  METHODS
  RCTs in implant dentistry were retrieved through electronic and hand searches. Risk of bias in individual studies was assessed focusing on study design, outcome assessment and clinical relevance. Associations between quality items and year of publication of RCTs or reporting of statistically significant outcomes were tested.
  
  
  RESULTS
  Among the 495 originally screened manuscripts published from 1989 to April 2011, 276 RCTs were assessed in this SR; 59% of them were published between 2006 and 2011. RCTs were mainly parallel (65%), with a single centre (83%) and a superiority design (88%). Trials in implant dentistry showed several methodological flaws: only 37% showed a random sequence generation at low risk of bias, 75% did not provide information on allocation concealment, only 12% performed a correct sample size calculation, the examiner was blind solely in 42% of studies where blinding was feasible. In addition, only 21% of RCTs declared operator experience and 31% reported patient-related outcomes. Many quality items improved over time. Allocation concealment at high risk of bias (p = 0.0125), no information on drop-out (p = 0.0318) and lack of CONSORT adherence (p = 0.0333) were associated with statistically significant reported outcomes.
  
  
  CONCLUSIONS
  The overall quality of reporting of RCTs in implant dentistry is poor and only partially improved in the last years. Caution is suggested when interpreting these RCTs since risk of bias was associated with higher chance of reporting of statistically significant results.
authors.affiliation: Department of Periodontology, University of Florence, Florence, Italy. cairofrancesco@virgilio.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Cairo
authors.forename: Ignacio
authors.initials: I
authors.lastname: Sanz
authors.forename: Paula
authors.initials: P
authors.lastname: Matesanz
authors.forename: Michele
authors.initials: M
authors.lastname: Nieri
authors.forename: Umberto
authors.initials: U
authors.lastname: Pagliaro
mesh_terms: D015982:Bias; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D055094:Evidence-Based Dentistry; D019983:Guideline Adherence; D006801:Humans; D017410:Practice Guidelines as Topic; D011643:Publishing; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D012107:Research Design / Q000592:standards*; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants