Clin Oral Invest DOI 10.1007/s00784-013-1017-0

ORIGINAL ARTICLE

The 100 most cited articles in dentistry

Javier F. Feijoo & Jacobo Limeres & Marta Fernández-Varela & Isabel Ramos & Pedro Diz

Received: 17 October 2012 /Accepted: 4 June 2013 # Springer-Verlag Berlin Heidelberg 2013

Abstract opinion (19 %). The most common area of study was peri- Objectives To identify the 100 most cited articles published odontology (43 % of articles). in dental journals. Conclusions To our knowledge, this is the first report of the Materials and methods A search was performed on the top-cited articles in Dentistry. There is a predominance of Institute for Scientific Information (ISI) for clinical studies, particularly case series and narrative the most cited articles in all the journals included in the reviews/expert opinions, despite their low-evidence level. Journal Citation Report (2010 edition) in the category of The focus of the articles has mainly been on “Dentistry, Oral Surgery, and Medicine”. Each one of the and implantology, and the majority has been published in the 77 journals selected was analyzed using the Cited Reference highest dental journals. Search tool of the ISI Web of Science database to identify the Clinical significance The number of citations that an article most cited articles up to June 2012. The following informa- receives does not necessarily reflect the quality of the re- tion was gathered from each article: names and number of search, but the present study gives some clues to the topics authors, journal, year of publication, type of study, method- and authors contributing to major advances in Dentistry. ological design, and area of research. Results The number of citations of the 100 selected articles Keywords Most cited articles . Dentistry . ISI web of varied from 326 to 2050. All articles were published in 21 of knowledge . Impact factor the 77 journals in the category. The journals with the largest number of the cited articles were the Journal of Clinical Periodontology (20 articles), the Journal of Periodontology Introduction (18 articles), and the Journal of Dental Research (16 articles). There was a predominance of clinical research (66 %) over One of the most widely used methods for evaluating the basic research (34 %). The most frequently named author academic importance of an article in a specific area of was Socransky SS, with 9 of the top 100 articles, followed by knowledge is to determine the number of times that that Lindhe J with 7. The decades with most articles published of publication has been cited by other authors [1]. It has been the 100 selected were 1980–1989 (26 articles) and 1990– speculated that the number of citations that an article re- 1999 (25 articles). The most common type of article was the ceives may express the capacity of that article to generate case series (22 %), followed by the narrative review/expert changes in clinical practice, discussion, controversy, or fur- ther research [2]. However, there is considerable debate regarding the value of citation rates to assess the quality of : : : : research or the relevance of its authors [3]. There is a possi- J. F. Feijoo J. Limeres M. Fernández-Varela I. Ramos P. Diz bility of temporal bias in the citation analysis because a paper Grupo de Investigación en Odontología Médico-Quirúrgica (OMEQUI). School of Medicine and Dentistry, Santiago de tends to accumulate citations over time; however, as the Compostela University, Santiago de Compostela A Coruña, Spain content of these papers is absorbed into current knowledge, citation rates may then fall progressively. In contrast, recent * P. Diz ( ) articles may not have had sufficient publication time to School of Medicine and Dentistry, Special Needs Unit, c/Entrerríos sn, 15782 Santiago de Compostela A Coruña, Spain generate high-citation rates. There are no indices that enable e-mail: [email protected] us to determine whether an article is more useful to those Clin Oral Invest clinicians who can apply its concepts in daily practice— clinical trials, case–control studies, cohort studies, animal stud- meaning that an article can be widely read but hardly ever ies, in vitro studies, new materials or techniques, narrative cited—or to investigators who need to be cited in order to review/expert opinion, systematic review/meta-analysis, or case achieve financial support or personal promotion [4]. However, series) and level of evidence [18], specific area of study (adhe- it has been demonstrated that citation analysis in specific areas sion restorations, caries, behavior management, implantology, of knowledge correlates well with other indices of scientific oral medicine/pathology, bone morphology/histology, pediatric recognition [5], and this resource has therefore achieved great dentistry, orthodontics, endodontics, , periodontol- popularity for the quantification of the citation impact of a ogy, saliva/biochemistry, or orofacial pain-dysfunction/pain country, a journal, an article, an author, a specialty, or a given syndrome), and the year of publication. disease [3, 6–8]. Two independent reviewers performed the selection of the Since 1945, the Institute for Scientific Information (ISI) articles. When there was discrepancy, the opinion of a third has been compiling the most relevant bibliometric informa- reviewer was requested to achieve consensus. tion from published scientific articles, although the , a specific tool to quantify citations, was not initiated until 1962. At the present time, this resource is Results called the Science Citation Index Expanded and it forms a section of the Web of Science [9]. This platform for The number of citations of the 100 articles selected varied bibliometric analysis has been used to identify the most between 326 and 2,050; each of the first 4 articles of the widely cited articles in different fields of medical science, ranking exceeded 1,000 citations and each of the first 35 had including general surgery [10], otorhinolaryngology [11], more than 500 citations (Table 1). Although it is clear that we dermatology [12], neurosurgery [13], urology [14], rehabil- cannot make a specific comment about all the papers individ- itation [15], and ophthalmology [8]. To our knowledge, no ually, we would like to do this at least for the three most citation analysis has been published in the field of dentistry, relevant ones. The most cited paper to date, with 2,050 cita- although this has been undertaken in some dental specialties, tions, was a review of the extracellular matrix metalloprotein- such as endodontics [16], and in journals of the specialty, ases and their role in the development of certain pathological such as the British Journal of Oral and Maxillofacial conditions, such as ; that article was pub- Surgery [17]. lished in 1993 by Henning Birkedal-Hansen et al. (Table 1)in The objective of the present study was to use these the journal Critical Reviews in Oral Biology and Medicine. bibliometric resources to identify the 100 most cited articles The following article, with 1,765 citations, was a report of the published in dental journals and to analyze their principal study published in the International Journal of Oral Surgery characteristics. in 1981 by Ragnar Adell et al. (from the group led by Per- Ingvar Brånemark) on the rehabilitation of the edentulous jaw using osseointegrated implants, with an initial phase of Material and methods standardization of the surgical and prosthetic techniques and a second phase of 5 to 9 years of follow-up of 895 For the purpose of this study, we selected the 77 journals implants (Table 1). The third most cited article, with 1,480 included in the category “Dentistry, Oral Surgery, and citations, had the title Experimental in Man and Medicine” in the database of the 2010 edition of the Journal was published in 1965 by Harald Loë et al. (Table 1)in Citation Report: Science Edition,asectionoftheWebof the Journal of Periodontology. That was a simple clinical Science [9]. The journals Critical Reviews in Oral Biology study with only 12 volunteers and the aim of the authors and Medicine, now a section of the Journal of Dental were to investigate the consequences of the interruption of Research,andtheInternational Journal of Oral Surgery,now toothbrushing and of any other oral hygiene procedure on known as the International Journal of Oral and Maxillofacial the deposition of and the appearance of Surgery, were also reviewed. Using the Cited Reference Search gingivitis. tool of the ISI Web of Knowledge, we determined the number Twenty-five articles were attributed to a single author and of citations of all the articles published in those journals from 18 articles to two authors, while the number of authors 1945 through June 2012. The 100 most cited articles were exceeded six in 12 publications. In quantitative terms, the selected and the following information was compiled for each author with most articles was Sigmund S. Socransky, with 9 one: ranking based on the number of citations, number and articles of the 100 selected articles, followed by Jan Lindhe names of the authors, journal in which published and the 2011 with 7, Harald Löe, Jørgen Slots, and Anne D. Haffajee with Journal Citation Report: Science Edition impact factor of the 6 articles each, and Sture R. Nyman with 5 (Table 2). journal, type of study (basic or clinical), methodological design Qualitatively, the following names stood out when consider- (case report, classifications or tools for evaluating results, ing only those authors with more than one publication Clin Oral Invest

Table 1 The 100 most cited articles in dentistry

Ranking Reference (2011 JCR Science Edition impact factor; evidence level, EL) Citations

1 Birkedal-Hansen H, Moore WG, Bodden MK, Windsor LJ, Birkedal-Hansen B, DeCarlo A et al. (1993). Matrix 2,050 metalloproteinases: a review. Crit Rev Oral Biol Meda 4:197–250. (3.486; EL 5) 2 Adell R, Lekholm U, Rockler B, Brånemark PI (1981). A 15-year study of osseointegrated implants in the treatment 1,765 of the edentulous jaw. Int J Oral Surgb 10:387–416. (1.506; EL 4) 3 Löe H, Theilade E, Jensen SB (1965). Experimental gingivitis in man. J Periodontol 36:177–187. (2.602; EL 4) 1,480 4 Löe H (1967). Gingival index plaque index and retention index systems. J Periodontol 38:610–616. (2.602; EL 5) 1,329 5 Albrektsson T, Zarb G, Worthington P, Eriksson AR (1986). The long-term efficacy of currently used dental implants: 997 a review and proposed criteria of success. Int J Oral Maxillofac Implants 1:11–25. (1.776; EL 5) 6 Buonocore MG (1955). A simple method of increasing the adhesion of acrylic filling materials to enamel surfaces. 954 J Dent Res 34:849–853. (3.486; EL 5) 7 Adell R, Eriksson B, Lekholm U, Brånemark PI, Jemt T (1990). Long-term follow-up study of osseointegrated implants 937 in the treatment of totally edentulous jaws. Int J Oral Maxillofac Implants 5: 347–359. (1.776; EL 4) 8 Socransky SS, Haffajee AD, Cugini MA, Smith C, Kent RL Jr (1998). Microbial complexes in subgingival plaque. 960 J Clin Periodontol 25:134–144. (2.996; EL 4) 9 Donath K, Breuner G (1982). A method for the study of undecalcified bones and teeth with attached soft-tissues— 887 the Sage–Schliff (sawing and grinding) technique. J Oral Pathol Med 11:318–326. (1.628; EL 5) 10 Marx RE, Carlson ER, Eichstaedt RM, Schimmele SR, Strauss JE, Georgeff KR (1998). Platelet-rich plasma: growth 748 factor enhancement for bone grafts. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 85:638–46. (1.455; EL 5) 11 Gold OG, Jordan HV, Vanhoute J (1973). Selective medium for streptococcus-mutans. Arch Oral Biol 18:1357–1364. 685 (1.603; EL 5) 12 Slots J, Genco RJ (1984). Black-pigmented Bacteroides species, species, and Actinobacillus 682 Actinomycetemcomitans in human periodontal-disease—virulence factors in colonization, survival, and tissue destruction. J Dent Res 63:412–421. (3.486; EL 5) 13 Ruggiero SL, Mehrotra B, Rosenberg TJ, Engroff SL (2004). Osteonecrosis of the jaws associated with the use of 690 bisphosphonates: a review of 63 cases. J Oral Maxillofac Surg 62:527–534. (1.640; EL 4) 14 Tanner AC, Haffer C, Bratthall GT, Visconti RA, Socransky SS (1979). Study of the bacteria associated with advancing 648 periodontitis in man. J Clin Periodontol 6:278–307. (2.996; EL 4) 15 Ainamo J, Bay I (1975). Problems and proposals for recording gingivitis and plaque. Int Dent J 25:229–235. (0.963; EL 5) 643 16 Zambon JJ (1985). Actinobacillus Actinomycetemcomitans in human periodontal-disease. J Clin Periodontol 12:1–20. 628 (2.996; EL 5) 17 Beck J, Garcia R, Heiss G, Vokonas PS, Offenbacher S (1996). Periodontal disease and cardiovascular disease. 618 J Periodontol 67:1123–1137. (2.602; EL 3) 18 Kakehash S, Stanley HR, Fitzgerald RJ (1965). Effects of surgical exposures of dental pulps in germ-free and conventional 617 laboratory rats. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 20:340–349. (1.455; EL 5) 19 Marx RE (2003). Pamidronate (Aredia) and zoledronate (Zometa) induced avascular necrosis of the jaws: a growing 606 epidemic. J Oral Maxillofac Surg 61:1115–1117. (1.640; EL 4) 20 Nyman S, Lindhe J, Karring T, Rylander H (1982). New attachment following surgical-treatment of human periodontal- 604 disease. J Clin Periodontol 9:290–296. (2.996; EL 5) 21 Feilzer AJ, Degee AJ, Davidson CL (1987). Setting stress in composite resin in relation to configuration of the restoration. J 585 Dent Res 66:1636–1639. (3.486; EL 5) 22 Houston WJB (1983). The analysis of errors in orthodontic measurements. Am J Orthod Dentofacial Orthop 83:382–390. 577 (1.381; EL 5) 23 Mombelli A, van Oosten MA, Schurch E Jr, Land NP (1987). The microbiota associated with successful or failing 570 osseointegrated titanium implants. Oral Microbiol Immunol 2:145–151. (2.807; EL 4) 24 Oleary TJ, Naylor JE, Drake RB (1972). Plaque control record. J Periodontol 43:38–40. (2.602; EL 5) 553 25 Slots J, Listgarten MA (1998). Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans 544 in human periodontal-diseases. J Clin Periodontol 15:85–93. (2.996; EL 5) 26 Moorrees CF, Fanning EA, Hunt EE Jr (1963). Age variation of formation stages for ten permanent teeth. J Dent Res 540 42:1490–1502. (3.486; EL 4) 27 Buser D, Mericske-Stern R, Bernard JP, Behneke A, Behneke N, Hirt HP et al. (1997). Long-term evaluation of non- 539 submerged ITI implants. Part 1: 8-year life table analysis of a prospective multi-center study with 2,359 implants. Clin Oral Implants Res 8:161–172. (2.514; EL 4) 28 Listgarten MA, Hellden l (1978). Relative distribution of bacteria at clinically healthy and periodontally diseased sites in 533 humans. J Clin Periodontol 5:115–132. (2.996; EL 4) 29 Kornman KS, Crane A, Wang HY, di Giovine FS, Newman MG, Pirk FW et al. (1997). The interleukin-1 genotype as a 531 severity factor in adult periodontal disease. J Clin Periodontol 24:72–77. (2.996; EL 4) 30 Van Meerbeek B, De Munck J, Yoshida Y, Inoue S, Vargas M, Vijay P et al. (2003). Buonocore Memorial 527 Lecture—adhesion to enamel and dentin: current status and future challenges. Oper Dent 28:215–235. (1.238; EL 5) 31 Socransky SS, Haffajee AD (1992). The bacterial etiology of destructive periodontal disease—current concepts. 521 J Periodontol 63:322–331. (2.602; EL 5) 32 Turesky S, Gilmore ND, Glickman I (1970). Reduced plaque formation by the chloromethyl analog of vitamin C. 521 J Periodontol 41:41–43. (2.602; EL 5) 33 Grossi SG, Zambon JJ, Ho AW, Koch G, Dunford RG, Machtei EE et al. (1994). Assessment of risk for periodontal- 518 disease. Part 1: risk indicators for attachment loss. J Periodontol 65:260–267. (2.602; EL 4) 34 Gottlow J, Nyman S, Lindhe J, Karring T, Wennström J (1986). New attachment formation in the human 518 by guided tissue regeneration—case reports. J Clin Periodontol 13:604–616. (2.996; EL 5) 35 Theilade E, Wright WH, Jensen SB, Löe H (1966). Experimental gingivitis in man. II. A longitudinal clinical and 507 bacteriological investigation. J Periodontal Res 1:1–13. (1.686; EL 4) Clin Oral Invest

Table 1 (continued) Ranking Reference (2011 JCR Science Edition impact factor; evidence level, EL) Citations

36 Slots J (1979). Subgingival microflora and periodontal-disease. J Clin Periodontol 6:351–382. (2.996; EL 4) 498 37 Jaffin RA, Berman CL (1991). The excessive loss of Brånemark fixtures in type-IV bone—a 5-year analysis. 487 J Periodontol 62:2–4. (2.602; EL 4) 38 Löe H, Schiott CR (1970). The effect of mouthrinses and topical application of on the development 482 of dental plaque and gingivitis in man. J Periodontal Res 5:79–83. (1.686; EL 4) 39 Greenspan JS, Daniels TE, Talal N, Sylvester RA (1974). Histopathology of Sjogren’s syndrome in labial salivary-gland 479 biopsies. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 37:217–229. (1.455; EL 5) 40 Russell AL (1956). A system of classification and scoring for prevalence surveys of periodontal disease. J Dent Res 35: 476 350–359. (3.486; EL 5) 41 Greene JC, Vermillion JR (1964). Simplified oral hygiene index. J Am Dent Assoc 68:7–13. (1.773; EL 5) 476 42 Brånemark PI (1983). Osseointegration and its experimental background. J Prosthet Dent 50:399–410. (1.324; EL 5) 472 43 Laskin DM (1969). Etiology of pain-dysfunction syndrome. J Am Dent Assoc 79:147–153. (1.773; EL 5) 468 44 Hirschfeld l, Wasserman B (1978). Long-term survey of tooth loss in 600 treated periodontal patients. J Periodontol 468 49:225–237. (2.602; EL 3) 45 Quigley GA (1962). Comparative cleansing efficiency of manual and power brushing. J Am Dent Assoc 65: 26–29. 465 (1.773; EL 2) 46 Dzink JL, Socransky SS, Haffajee AD (1988). The predominant cultivable microbiota of active and inactive lesions of 461 destructive periodontal-diseases. J Clin Periodontol 15:316–323. (2.996; EL 4) 47 Corah NL (1969). Development of a dental anxiety scale. J Dent Res 48:596. (3.486; EL 5) 460 48 Marx RE, Sawatari Y, Fortin M, Broumand V (2005). Bisphosphonate-induced exposed bone (osteonecrosis/osteopetrosis) 450 of the jaws: Risk factors, recognition, prevention, and treatment. J Oral Maxillofac Surg 63:1567–1575. (1.640; EL 4) 49 Ainamo J, Barmes D, Beagrie G, Cutress T, Martin J, Sardo-Infirri J (1982). Development of the world-health-organization 458 (WHO) community periodontal index of treatment needs (CPITN). Int Dent J 32:281–291. (0.963; EL 5) 50 Gottlow J, Nyman S, Karring T, Lindhe J (1984). New attachment formation as the result of controlled tissue regeneration. 441 J Clin Periodontol 11:494–503. (2.996; EL 5) 51 Nyman S, Gottlow J, Karring T, Lindhe J (1982). The regenerative potential of the periodontal-ligament—an experimental 439 study in the monkey. J Clin Periodontol 9:257–265. (2.996; EL 5) 52 Socransky SS (1977). Microbiology of periodontal-disease—present status and future considerations. J Periodontol 425 48:497–504. (2.602; EL 5) 53 Page RC (1991). The role of inflammatory mediators in the pathogenesis of periodontal-disease. J Periodontal Res 26:230– 423 342. (1.686; EL 5) 54 Zach l, Cohen G (1965). Pulp response to externally applied heat. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 423 19:515–530. (1.455; EL 4) 55 Offenbacher S, Katz V, Fertik G, Collins J, Boyd D, Maynor G et al. (1996). Periodontal infection as a possible risk factor 430 for preterm low birth weight. J Periodontol 67:1103–1113. (2.602; EL 4) 56 Tallgren A (1972). Continuing reduction of residual alveolar ridges in complete denture wearers—mixed-longitudinal study 422 covering 25 years. J Prosthet Dent 27:120–132. (1.324; EL 3) 57 Sjögren U, Hagglund B, Sundqvist G, Wing K (1990). Factors affecting the long-term results of endodontic treatment. 417 J Endod 16:498–504. (2.880; EL 3) 58 Downs WB (1948). Variations in facial relationships—their significance in treatment and prognosis. Am J Orthod 416 Dentofacial Orthop 34:812–840. (1.381; EL 5) 59 Davidson CL, Degee AJ, Feilzer A (1984). The competition between the composite-dentin bond strength and the 416 polymerization contraction stress. J Dent Res 63:1396–1399. (3.486; EL 5) 60 Slots J, Bragd L, Wikström M, Dahlén G (1986). The occurrence of Actinobacillus actinomycetemcomitans, Bacteroides 414 gingivalis and Bacteroides intermedius in destructive periodontal-disease in adults. J Clin Periodontol 13:570–577. (2.996; EL 4) 61 Gronthos S, Brahim J, Li W, Fisher LW, Cherman N, Boyde A et al. (2002). Stem cell properties of human dental pulp stem 411 cells. J Dent Res 81:531–535. (3.486; EL 5) 62 Esposito M, Hirsch JM, Lekholm U, Thomsen P (1998). Biological factors contributing to failures of osseointegrated oral 407 implants. (II). Etiopathogenesis. Eur J Oral Sci 106:721–764. (1.878; EL 1) 63 Ashimoto A, Chen C, Bakker I, Slots J (1996). Polymerase chain reaction detection of 8 putative periodontal pathogens in 405 subgingival plaque of gingivitis and advanced periodontitis lesions. Oral Microbiol Immunol 11: 266–273. (2.807; EL 4) 64 Socransky SS (1970). Relationship of bacteria to the etiology of periodontal disease. J Dent Res 49:203–222. (3.486; EL 5) 404 65 Sundqvist G, Figdor D, Persson S, Sjögren U (1998). Microbiologic analysis of teeth with failed endodontic 403 treatment and the outcome of conservative re-treatment. Oral Sur Oral Med Oral Pathol Oral Radiol Endod 85:86–93. (1.455; EL 4) 66 Melcher AH (1976). Repair potential of periodontal tissues. J Periodontol 47:256–260. (2.602; EL 5) 400 67 Goodson JM, Tanner AC, Haffajee AD, Sornberger GC, Socransky SS (1982). Patterns of progression and regression of 394 advanced destructive periodontal-disease. J Clin Periodontol 9:472–481. (2.996; EL 4) 68 Fitzgerald RJ, Keyes PH (1960). Demonstration of the etiologic role of streptococci in experimental caries in the hamster. J 393 Am Dent Assoc 61:9–19. (1.773; EL 5) 69 Keyes PH (1958). Dental caries in the molar teeth of rats. II. A method for diagnosing and scoring several types of lesions 392 simultaneously. J Dent Res 37:1088–1099. (3.486; EL 5) 70 Van Meerbeek B, Inokoshi S, Braem M, Lambrechts P, Vanherle G (1992). Morphological aspects of the resin-dentin 389 interdiffusion zone with different dentin adhesive systems. J Dent Res 71:1530–1540. (3.486; EL 5) 71 Bjork A (1963). Variations in the growth pattern of the human mandible: longitudinal radiographic study by the implant 388 method. J Dent Res 42:400–411. (3.486; EL 3) Clin Oral Invest

Table 1 (continued) Ranking Reference (2011 JCR Science Edition impact factor; evidence level, EL) Citations

72 De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem M et al. (2005). A critical review of the 388 durability of adhesion to tooth tissue: methods and results. J Dent Res 84:118–132. (3.486; EL 5) 73 Buser D, Brägger U, Lang NP, Nyman S (1990). Regeneration and enlargement of jaw bone using guided tissue 385 regeneration. Clin Oral Implants Res 1:22–32. (2.514; EL 4) 74 Haraszthy VI, Zambon JJ, Trevisan M, Zeid M, Genco RJ (2000). Identification of periodontal pathogens in atheromatous 385 plaques. J Periodontol 71:1554–1560. (2.602; EL 4) 75 Esposito M, Hirsch JM, Lekholm U, Thomsen P (1998). Biological factors contributing to failures of osseointegrated oral 385 implants (I). Success criteria and epidemiology. Eur J Oral Sci 106:527–555. (1.878; EL 1) 76 Cawood JI, Howell RA (1988). A classification of the edentulous jaws. Int J Oral Maxillofac Surg 17: 232–236. (1.506; EL 5) 382 77 Socransky SS, Haffajee AD, Goodson JM, Lindhe J (1984). New concepts of destructive periodontal-disease. J Clin 379 Periodontol 11:21–32. (2.996; EL 5) 78 Sano H, Shono T, Sonoda H, Takatsu T, Ciucchi B, Carvalho R et al. (1994). Relationship between surface-area for adhesion 376 and tensile bond strength—evaluation of a micro-tensile bond test. Dent Mater 10:236–240. (3.135; EL 5) 79 Sodek J, Ganss B, McKee MD (2000). Osteopontin. Crit Rev Oral Biol Meda 11:279–303. (3.486; EL 5) 375 80 Dworkin SF, Huggins KH, LeResche L, Von Korff M, Howard J, Truelove E et al. (1990). Epidemiology of signs and symptoms 373 in temporomandibular disorders—clinical signs in cases and controls. J Am Dent Assoc 120:273–281. (1.773; EL 4) 81 Hammarstrom L (1997). Enamel matrix, development and regeneration. J Clin Periodontol 24:658–668. (2.996; EL 5) 372 82 Badersten A, Nilveus R, Egelberg J (1984). Effect of nonsurgical periodontal therapy. II. Severely advanced periodontitis. 371 J Clin Periodontol 11:63–76. (2.996; EL 4) 83 Schneider SW (1971). Comparison of canal preparations in straight and curved root canals. Oral Surg Oral Med Oral 371 Pathol Oral Radiol Endod 32:271–275. (1.455; EL 5) 84 Grossi SG, Genco RJ, Machtei EE, Ho AW, Koch G, Dunford R et al. (1995). Assessment of risk for periodontal-disease. II. 367 Risk indicators for alveolar bone loss. J Periodontol 66:23–29. (2.602; EL 3) 85 Solberg WK, Woo MW, Houston JB (1979). Prevalence of mandibular dysfunction in young adults. J Am Dent Assoc 363 98:25–34. (1.773; EL 4) 86 Axelsson P, Lindhe J (1978). Effect of controlled oral hygiene procedures on caries and periodontal-disease in adults. J Clin 357 Periodontol 5:133–151. (2.996; EL 4) 87 Urist MR, Strates BS (1971). Bone morphogenetic protein. J Dent Res 50:1392–1406. (3.486; EL 5) 354 88 Wilson AD, Kent BE (1972). New translucent cement for dentistry—glass ionomer cement. Br Dent J 132:133–135. (0.915; EL 5) 352 89 Jaffe HL (1953). Giant-cell reparative granuloma, traumatic bone cyst, and fibrous (fibro-osseous) dysplasia of the 352 jawbones. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 6:159–175. (1.455; EL 5) 90 Sano H, Takatsu T, Ciucchi B, Horner JA, Matthews WG, Pashley DH (1995). Nanoleakage—leakage within the hybrid 351 layer. Oper Dent 20:18–25. (1.238; EL 5) 91 Löe H, Anerud A, Boysen H, Morrison E (1986). Natural-history of periodontal-disease in man—rapid, moderate and no 341 loss of attachment in Sri Lankan laborers 14 to 46 years of age. J Clin Periodontol 13:431–440. (2.996; EL 3) 92 Steiner CC (1953). Cephalometrics for you and me. Am J Orthod Dentofacial Orthop 39:729–755. (1.381; EL 5) 341 93 Albrektsson T, Dahl E, Enbom L, Engevall S, Engquist B, Eriksson AR et al. (1988). Osseointegrated oral implants—a 336 Swedish multicenter study of 8,139 consecutively inserted Nobelpharma implants. J Periodontol 59:287–296. (2.602; EL 3) 94 Zambon JJ, Christersson LA, Slots J (1983). Actinobacillus actinomycetemcomitans in human periodontal- 334 disease—prevalence in patient groups and distribution of biotypes and serotypes within families. J Periodontol 54:707– 711. (2.602; EL 4) 95 Eriksson AR, Albrektsson T (1983). Temperature threshold levels for heat-induced bone tissue-injury—a vital-microscopic 334 study in the rabbit. J Prosthet Dent 50:101–117. (1.324; EL 5) 96 Listgarten MA, Lindhe J, Hellden I (1978). Effect of tetracycline and-or scaling on human periodontal-disease—clinical, 333 microbiological, and histological observations. J Clin Periodontol 5:246–247. (2.996; EL 2) 97 Tabak LA, Levine MJ, Mandel ID, Ellison SA (1982). Role of salivary mucins in the protection of the oral cavity. 331 J Oral Pathol Med 11:1–17. (1.628; EL 5) 98 Listgarten MA (1976). Structure of microbial flora associated with periodontal health and disease in man—light and 330 electron-microscopic study. J Periodontol 47:1–18. (2.602; EL 4) 99 Löe H, Anerud A, Boysen H, Smith M (1978). Natural-history of periodontal-disease in man—rate of periodontal 327 destruction before 40 years of age. J Periodontol 49:607–620. (2.602; EL 4) 100 Marx RE (2004). Platelet-rich plasma: Evidence to support its use. J Oral Maxillofac Surg 62:489–496. (1.640; EL 5) 326 a Crit Rev Oral Biol Med now included in J Dent Res b Int J Oral Surg now called Int J Oral Maxillofac Surg amongst the first 25 articles in the ranking: Harald Löe, who The decade with most articles published of the selected participated in the articles ranked 3 and 4; Ragnar Adell, Ulf 100 was 1980–1989 with 26 articles, followed by 1990– Lekholm, and Per-Ingvar Branemark, with the articles 1999 with 25 articles and 1970–1979 with 22. ranked 2 and 7; Sigmund S. Socransky, author of the papers There was a clear predominance of citations of publica- ranked 8 and 14; Robert E. Marx, responsible for the papers tions on clinical research over those on basic research (66 ranked 10 and 19; and Jørgen Slots, who collaborated in the and 34 articles, respectively). The most common methodo- papers ranked 12 and 25. logical designs were the case series (22 articles) and the Clin Oral Invest

Table 2 Authors with the largest number of articles included amongst Table 3 Type of study, methodological design, and specific field of the the 100 most cited articles 100 most cited articles in dentistry

Authors with more than 2 articles included in the top 100 Type of study Clinical=66 % Basic=34 % Name First Author Coauthor Last Author Total Socransky SS 5 1 3 9 Methodological design Animal studies=9 % (EL 5) (evidence level (EL)) Lindhe J 0 3 4 7 Case report=1 % (EL 5) Löe H 5 0 1 6 Classifications or tools for evaluating results=13 % (EL 5) Slots J 4 0 2 6 In vitro studies=7 % (EL 5) Haffajee AD 0 5 1 6 Narrative review/expert opinion=19 % (EL 5) Nyman S 2 2 1 5 New material or technique=5 % (EL 5) Marx RE 4 0 0 4 Case–control studies=11 % (EL 4) Listgarten MA 3 0 1 4 Case series=23 % (EL 4) Zambon JJ 2 2 0 4 Cohort studies=8 % (EL 3) Karring T 0 4 0 4 Randomized clinical trials=2 % (EL 2) Lekholm U 0 4 0 4 Systematic review/meta-analysis=2 % (EL 1) Albrektsson T 2 0 1 3 Area of research Periodontology=43 % Gottlow J 2 1 0 3 Implantology=11 % Genco RJ 0 1 2 3 Adhesive restorations=8 % Brånemark PI 1 1 1 3 Bone morphology/histology=7 % Eriksson AR 1 1 1 3 Endodontics=6 % Caries=5 % narrative review/expert opinion (19 articles). The predomi- Oral medicine/pathology=5 % nant area of research was periodontology (43 articles), Orthodontics=4 % followed at a considerable distance by implantology (11 Saliva/Biochemistry=4 % articles) and adhesive restorations (8 articles) (Table 3). Pain-dysfunction/orofacial pain syndrome=3 % The 100 articles selected were published in 21 journals. Oral hygiene=2 % The journal with the largest number of the articles cited was Pediatric dentistry=1 % the Journal of Clinical Periodontology with 20 articles, Behavior management=1 % followed by the Journal of Periodontology with 18 and the Journal of Dental Research with 16 (Table 4). article in the ranking was published in 1981 by Ragnar Adell et al. (Table 1)intheInternational Journal of Oral Surgery, Discussion which does not figure in the 2010 edition of the Journal Citation Report database as the journal is now called the As with other citation analyses, the present study has certain International Journal of Oral and Maxillofacial Surgery. limitations; most evident is that the Cited Reference Search Dentistry is a multidisciplinary field that has undergone enor- tool of the ISI Web of Knowledge does not automatically mous advances in recent decades, and this could have led to exclude self-citing [19] or the potential bias due to the prefer- numerous articles with a dental subject matter being published ence of authors to cite articles from the journal in which they in journals in other categories of the Journal Citation Report hope to publish their own paper [20]. In addition, citations and therefore not included in our series. appearing in books and in journals written in other languages Arbitrarily, articles that exceed the threshold of 100 cita- are not included in this database; other bibliographic re- tions are considered “classic articles” and usually represent sources, such as Google Scholar, have a broader citation- historical reference points in the development of a specific capture registry, though they are less effective at detecting area [22]. In the present series, the article that occupied citations from older articles [21]. The Journal Citation Report: position 100 in the ranking had 326 citations, which would Science Edition of the ISI Web of Knowledge is a dynamic imply that a large number of classic articles have been database in which the journals included in each category are omitted. updated annually. As a result, some articles with a high Forty-three percent of the articles in this series were number of citations may have been excluded if published in written exclusively by one or two authors, and there was a a journal that is no longer included in the “Dentistry, Oral noticeable lack of multi-center studies in the 100 articles Surgery, and Medicine” category. For example, the second selected. It has been suggested that studying the authors with Clin Oral Invest

Table 4 Journals in which the 100 most cited articles were Journal Name (2011 JCR Science Abbreviated name Number of articles published Edition impact factor) included in the top 100

Journal of Clinical Periodontology (2.996) J Clin Periodontol 20 Journal of Periodontology (2.602) J Periodontol 18 Journal of Dental Researcha (3.486) J Dent Res 16 Oral Surgery Oral Medicine Oral Pathology Oral Oral Surg Oral Med Oral 7 Radiology and Endodontics (1.455) Pathol Oral Radiol Endod Journal of the American Dental Association (1.773) J Am Dent Assoc 6 Journal of Oral and Maxillofacial Surgery (1.640) J Oral Maxillofac Surg 4 American Journal of Orthodontics and Dentofacial Am J Orthod Dentofacial 3 Orthopedics (1.381) Orthop Journal of Periodontal Research (1.686) J Periodontal Res 3 Journal of Prosthetic Dentistry (1.324) J Prosthetic Dent 3 Clinical Oral Implant Research (2.514) Clin Oral Implant Res 2 European Journal of Oral Sciences (1.878) Eur J Oral Sci 2 International Dental Journal (0.963) Int Dent J 2 International Journal of Oral and Implants (1.776) Int J Oral Maxillofac Implants 2 International Journal of Oral and Maxillofacial Int J Oral Maxillofac Surg J 2 Surgeryb(1.506) Journal of Oral Pathology and Medicine (1.628) Oral Pathol Med 2 Operative Dentistry (1.238) Oper Dent 2 Oral Microbiology and Immunology (2.807) Oral Microbiol Immunol 2 Archives of Oral Biology (1.603) Arch Oral Biol 1 a Crit Rev Oral Biol Med now British Dental Journal (0.915) Br Dent J 1 included in J Dent Res Dental Materials (3.135) Dent Mater 1 b Int J Oral Surg now called Int J Journal of Endodontics (2.880) J Endod 1 Oral Maxillofac Surg a high-citation index could constitute a voyeuristic activity, as journals with the highest impact factors and that those these authors have a disproportionate impact on their fields of journals are included in other categories of the Journal knowledge [23]. On this matter, a citation bias has been de- Citation Report [13]. Paradoxically, some relevant articles scribed that consists of a tendency to cite articles from influen- published before the decade of the 1960s could have been tial scientists, colleagues, or reviewers [19]. In addition, a omitted as there is no electronic version of those papers, a “snowball effect” has been described that refers to the tendency situation that significantly limits access to them. of some authors to cite certain studies simply because they In the present series, there has been a predominance of have previously received numerous citations rather than for articles with a clinical content over those reporting basic re- their content or quality [2]. The achievements of highly search. This finding has already been observed on analyzing the cited scientists can serve as a benchmark against which to most cited articles in other medical disciplines such as general measure the trajectory of other investigators [24]. surgery [10], anesthesia [25], and orthopedic surgery [2]. In It is considered that the true impact of a study cannot be some disciplines, especially those in the surgical field, the most evaluated adequately for at least 2 decades after its publica- extensively cited articles correspond to classifications or tools tion [25]. This could explain why the decades in which the for evaluating results [10]. Coinciding with the tendency ob- majority of the 100 selected articles were published were the served in other disciplines such as rehabilitation and urology 1980s and 1990s. This predominance of the most cited [14, 15], we found a predominance of case series and expert articles in the decade of the 1980s has also been observed opinions. The majority of articles in the present series were of in other specialties [2]. It has been suggested that older evidence levels 4 and 5 and, paradoxically, there were only 2 articles are usually cited more frequently, independently of randomized clinical trials and 2 systematic reviews/meta-anal- their current impact and that, in contrast, the impact of more yses; this confirms the absence of any correlation between the recently published papers is underestimated [26]. The inclu- level of evidence and the number of citations in the field of sion in the present series of only 9 articles published after the dentistry, as has been reported in other disciplines [15]. The year 2000 may be a reflection either that insufficient time has specific subject area of the most cited articles usually varies passed since their publication for citations to be accumulated from one decade to another [14]. In the present series, there was or that there is now a tendency to submit quality articles to a predominance of articles on periodontology, particularly on Clin Oral Invest the subject of microbiology, although other areas relevant to 2. Lefaivre KA, Shadgan B, O’Brien PJ (2011) 100 most cited articles – dentistry, such as osseointegration and adhesive restorations, in orthopaedic surgery. Clin Orthop Relat Res 469:1487 1497 3. Cheek J, Garnham B, Quan J (2006) What’s in a number? Issues in have been progressively incorporated. The appearance of a providing evidence of impact and quality of research(ers). Qual new pathological condition, such as bisphosphonate-related Health Res 16:423–435 osteonecrosis of the jaw, has led to a considerable number of 4. Bellini C (2012) Cited or read? Lancet 379:314 citations in a very few years; however, application of recent 5. Garfield E (1992) Of Nobel class, women in science, citation classics, and other essays. Curr Contents 35:3–12 technological advances in areas such as molecular biology and 6. Basu A (2006) Using ISI’s ‘highly cited researchers’ to obtain a genetics was not evident in the selected articles. country level indicator of citation excellence. Scientometrics It has been reported that the principal journals attract articles 68:361–375 that will presumably have a high-citation index, maintaining 7. Ibrahim GM, Carter Snead O 3rd, Rutka JT, Lozano AM (2012) The most cited works in epilepsy: trends in the “citation classics”. the impact factor of those journals [10] and justifying the Epilepsia 53:765–770 clustering of relevant articles in a limited number of journals, 8. Ohba N, Nakao K (2010) The 101 most frequently cited articles in particularly in those fields with high-citation density [27]. In the ophthalmology journals from 1850 to 1949. Arch Ophthalmol – present series, more than half of all the articles selected (n=54) 128:1610 1617 9. Science Thomas-Reuters. Available at: http://www.isinet.com. were published in only three journals: Journal of Clinical Accessed May, 2012. Periodontology, Journal of Periodontology,andJournal of 10. Paladugu R, Schein M, Gardezi S, Wise L (2002) One hundred Dental Research; this confirms the close relationship between citation classics in general surgical journals. World J Surg 26:1099– citations and impact. However, this premise was not observed 1105 11. Roy D, Hughes JP, Jones AS, Fenton JE (2002) Citation analysis of in other journals such as the Oral Surgery, Oral Medicine, Oral otorhinolaryngology journals. J Laryngol Otol 116:363–366 Pathology, Oral Radiology, and Endodontics journal, in which 12. Stern RS, Arndt KA (1999) Classic and near-classic articles in the seven of the articles in the present series were published (posi- dermatologic literature. Arch Dermatol 135:948–950 tion 4 in the journal ranking) though this journal, is in position 13. Ponce FA, Lozano AM (2010) Highly cited works in neurosurgery. Part I: the 100 top-cited papers in neurosurgical journals. J 30 of 77 in the impact factor ranking. This could have occurred Neurosurg 112:223–232 because the impact factor of a journal is not determined 14. Heldwein FL, Rhoden EL, Morgentaler A (2010) Classics of urol- solely by the number of citations of the most relevant ogy: a half century history of the most frequently cited articles – – articles, but rather on the total number of citations received (1955 2009). Urology 75:1261 1268 15. Shadgan B, Roig M, Hajghanbari B, Reid WD (2010) Top-cited over a given year by all the articles published in that journal articles in rehabilitation. Arch Phys Med Rehabil 91:806–815 in the previous 2 years, or because of other factors, such as 16. Fardi A, Kodonas K, Gogos C, Economides N (2011) Top-cited the progressive increase in the relevance of some journals at articles in endodontic journals. J Endod 37:1183–1190 the cost of others. 17. Brennan PA, Habib A (2011) What are we reading? A study of downloaded and cited articles from the British Journal of Oral and Maxillofacial Surgery in 2010. Br J Oral Maxillofac Surg 49:527– 531 Conclusions 18. OCEBM Levels of Evidence Working Group. The Oxford 2011 Levels of Evidence. Oxford Centre for Evidence-Based Medicine. Available at: http://www.cebm.net/index.aspx?o=5653. Accessed To our knowledge, this is the first report of the top-cited 1 May 2013. articles in Dentistry. There is a predominance of clinical 19. Dumont JE (1989) The bias of citations. Trends Biochem Sci studies, particularly case series and narrative reviews/expert 14:327–328 opinions despite their low-evidence level, mainly focused on 20. Seglen PO (1997) Why the impact factor of journals should not be used for evaluating research. BMJ 314:498–502 periodontology and implantology, and these articles are usu- 21. Bakkalbasi N, Bauer K, Glover J, Wang L (2006) Three options for ally published in the highest impact factor dental journals. citation tracking: Google Scholar, and Web of Science. Biomed Digit Libr 29:7 22. Andersen J, Belmont J, Cho CT (2006) Journal impact factor in the era of expanding literature. J Microbiol Immunol Infect 39:436–443 Conflict of interest The authors declare that they have no conflict of 23. Parker JN, Lortie C, Allesina S (2010) Characterizing a scientific interest. elite: the social characteristics of the most highly cited scientists in environmental science and ecology. Scientometrics 85:129–143 24. Hermanowicz J (2005) Classifying universities and their depart- ments: a social world perspective. J Higher Educ 61:26–55 25. Baltussen A, Kindler CH (2004) Citation classics in anesthetic References journals. Anesth Analg 98:443–451 26. Bohannon RW, Roberts D (1991) Core journals of rehabilitation: identification through index analysis. Int J Rehabil Res 14:333–336 1. Moed HF (2009) New developments in the use of citation analysis 27. Ioannidis JP (2006) Concentration of the most-cited papers in the in research evaluation. Arch Immunol Ther Exp (Warsz) 57:13–18 scientific literature: analysis of journal ecosystems. PLoS One 1:e5