title: Evolving Trends in Endodontic Research: An Assessment of Published Articles in 2 Leading Endodontic Journals.
abstract: BACKGROUND
  The aim of this study was to evaluate and analyze the evolving trends in endodontic research in 2 leading endodontic journals (ie, Journal of Endodontics and International Endodontic Journal) in articles published from January 2009 to December 2013. The differences in content between this period and a 10-year earlier period from January 1999 to December 2003 were also evaluated.
  
  
  METHODS
  Each journal's content was accessed through the web edition. For each article, the following parameters were recorded: number of authors, article type, number of affiliations, field of study, source of article, and geographic origin. The recorded data were analyzed using both descriptive and analytic statistics.
  
  
  RESULTS
  During 2009-2013 (second period), the mean number of authors per article increased significantly compared with 1999-2003 (first period). The main volume of the literature in both periods and journals was original research articles. The number of published reviews increased significantly from the first to the second study period in contrast to case reports/clinical articles, which presented a significant decrease. "Endodontic materials" was the most prevalent thematic category in both study periods. The number of published articles related to "biology" and "chemical preparation and disinfection" increased significantly from the first to the second study period. On the contrary, the number of articles regarding "obturation and microleakage" presented a considerable decrease at the same time. The United States was the leading country in the number of publications in the first period followed by Brazil. In the second period, this rank was reversed with Brazil becoming the leading country followed by the United States.
  
  
  CONCLUSIONS
  In the last 15 years, the progress of the specialty of endodontology was apparent as shown through the trends and shifts in research orientation in published articles in the 2 leading endodontic journals. The results of the present reviewing process encourage both journals to publish well-designed research projects with a high degree of difficulty, thus contributing to a more evidence-based approach of endodontology.
authors.affiliation: Department of Endodontics, Dental School, University of Athens, Athens, Greece. Electronic address: gtzanet@dent.uoa.gr.
authors.forename: Giorgos N
authors.initials: GN
authors.lastname: Tzanetakis
authors.affiliation: Private Practice Limited to Endodontics, Patras, Greece.
authors.forename: Spyridon
authors.initials: S
authors.lastname: Stefopoulos
authors.affiliation: Private Practice Limited to Endodontics, Nicosia, Cyprus.
authors.forename: Alexios L
authors.initials: AL
authors.lastname: Loizides
authors.affiliation: Department of Endodontics, Dental School, University of Athens, Athens, Greece.
authors.forename: Vasileios D
authors.initials: VD
authors.lastname: Kakavetsos
authors.affiliation: Department of Endodontics, Dental School, University of Athens, Athens, Greece.
authors.forename: Evangelos G
authors.initials: EG
authors.lastname: Kontakiotis
mesh_terms: D015706:Bibliometrics; D001938:Brazil; D004708:Endodontics / Q000639:trends*; D006801:Humans; D011643:Publishing / Q000639:trends*; D014481:United States
keywords: Article characteristics; bibliometric study; endodontic literature