The continually high impact factor of Periodontology 2000 (7.861 for 2018), the level of which is unprecedented among dental journals, prompted the present bibliometric analysis of the Journal. Since the inception of Periodontology 2000 in 1993 and until July 2019, the top 100 most-cited articles have received a total of 21,276 (Web of Science), 23,009 (Elsevier's Scopus), and 43,518 (Google Scholar) citations. The citations of the 100 most-cited articles were found to vary from 118 to 827 (Web of Science), 10 to 1069 (Scopus), and 15 to 2028 (Google Scholar). Three articles had more than 600 (Web of Science) citations, 5 had between 400 and 600 citations, 25 had between 200 and 400 citations, and 67 had between 100 and 200 citations. The first authors of the 100 most-cited articles were based in the USA (51%), Switzerland (14%), and Australia (10%). The 5 dental institutions with the most frequently cited articles were The Forsyth Institute, USA (9 articles), The University of Queensland, Australia (8 articles), University of Bern, Switzerland (7), University of Texas Health Science Center at San Antonio, USA (6 articles), and University of Washington, USA, and Temple University School of Dentistry, USA (5 articles each). The likely reason for the high impact factor of Periodontology 2000 is publication of insightful and timely review articles produced by eminent researchers and clinicians from a wide range of dental institutions and countries.