title: From initial case report to randomized clinical trial through 20 years of research in periodontal therapy.
abstract: OBJECTIVE
  Case reports (CRs) are often the first publication of a new treatment, but randomized clinical trials (RCTs) are needed to confirm the data. The aim of this study was to evaluate how many therapies published as CRs were followed by RCTs of these therapies over a 20-year period.
  
  
  METHODS
  Two researchers conducted a search through international periodontal journals and found the CRs on periodontal treatments published from 1984 to 1986. Subsequent electronic searches made it possible to verify how many of the treatments published as CRs were also investigated through RCTs over the following 20 years.
  
  
  RESULTS
  Thirty-one different therapies were selected out of the 33 published CRs; 15 (48%) of these 31 treatments were investigated by RCTs over the next 20 years.
  
  
  CONCLUSIONS
  As 52% of the CRs were not validated by RCTs, practitioners should view their results with caution.
authors.affiliation: Department of Periodontology, Dental School, University of Florence, Florence, Italy. michelenieri@gmail.com
authors.forename: Michele
authors.initials: M
authors.lastname: Nieri
authors.forename: Daniele
authors.initials: D
authors.lastname: Saletta
authors.forename: Jacopo
authors.initials: J
authors.lastname: Buti
authors.forename: Umberto
authors.initials: U
authors.lastname: Pagliaro
authors.forename: Luisa
authors.initials: L
authors.lastname: Guidi
authors.forename: Roberto
authors.initials: R
authors.lastname: Rotundo
authors.forename: Giovanpaolo Pini
authors.initials: GP
authors.lastname: Prato
mesh_terms: D015706:Bibliometrics; D018865:Dental Research / Q000379:methods*; D006801:Humans; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010510:Periodontal Diseases / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic; D054928:Validation Studies as Topic