title: Trend in dental research output in Iran over a period of 20 years (1990-2009).
abstract: BACKGROUND
  The number of scientific papers is a conventional metric for the measurement of a country's research performance in a particular area.
  
  
  OBJECTIVE
  To evaluate the trend in Iranian publications of dental research results in peer-reviewed international scientific journals over the period 1999-2009, using national and international databases, and to compare the results with other countries.
  
  
  METHODS
  The search process was performed by two independent persons in PubMed and Iranian Medline (IranMedex). Data extraction included the year of publication, total number of dental papers in each year, total number of Iranian dental papers in each year and number of papers with a high level of evidence; these were compared with those in other Asian countries.
  
  
  RESULTS
  The total number of dental articles indexed in PubMed during the studied period was 207,689, with 671 being written by researchers who stated their affiliation as Iran. Although the proportion of Iranian dental articles to all published dental articles was 0.01% in 1990, this increased to 1.4% in 2009. Of all clinical trials indexed in PubMed from 1990 to 2009, only 0.62% had an author from Iran. The collaboration rate of authors ranged between 1 and 10. Turkey and Iran had a larger number of dental research publications compared with other Asian countries assessed in this study.
  
  
  CONCLUSIONS
  During the last two decades, there has been a considerable increase in the number of dental papers by Iranian researchers indexed in the PubMed database.
authors.affiliation: Kerman Oral and Dental Diseases Research Centre, Kerman, Iran.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Sadeghi
authors.forename: Arash
authors.initials: A
authors.lastname: Shahravan
authors.forename: Ali Akbar
authors.initials: AA
authors.lastname: Haghdoost
authors.forename: Saeed
authors.initials: S
authors.lastname: Asgary
authors.forename: Maryam
authors.initials: M
authors.lastname: Rad
mesh_terms: D001211:Asia, Western; D001319:Authorship; D015706:Bibliometrics; D002681:China; D002986:Clinical Trials as Topic; D018865:Dental Research / Q000706:statistics & numerical data / Q000639:trends*; D006801:Humans; D007492:Iran; D007564:Japan; D016239:MEDLINE; D009935:Organizational Affiliation; D010506:Periodicals as Topic; D039781:PubMed; D011643:Publishing / Q000706:statistics & numerical data / Q000639:trends; D012196:Review Literature as Topic