Citation classics in periodontology: a controlled study

AIM: The aims of this study were to identify the most cited articles in Periodontology published from January 1990 to March 2005; and to analyse the differences between citation Classics and less cited articles. MATERIAL AND METHODS: The search was carried out in four international periodontal journals: Journal of Periodontology, Journal of Clinical Periodontology, International Journal of Periodontics and Restorative Dentistry and Journal of Periodontal Research. The Classics, that are articles cited at least 100 times, were identified using the Science Citation Index database. From every issue of the journals that contained a Classic, another article was randomly selected and used as a Control. RESULTS: Fifty-five Classics and 55 Controls were identified. Classic articles were longer, used more images, had more authors, and contained more self-references than Controls. Moreover Classics had on the average a bigger sample size, often dealt with etiopathogenesis and prognosis, but were rarely controlled or randomized studies. CONCLUSIONS: Classic articles play an instructive role, but are often non-Controlled studies.     

A bibliometric analysis of Periodontology 2000

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.     

The 100 most cited articles in dentistry

Objectives

To identify the 100 most cited articles published in dental journals.

Materials and methods

A search was performed on the Institute for Scientific Information (ISI) Web of Science for the most cited articles in all the journals included in the Journal Citation Report (2010 edition) in the category of “Dentistry, Oral Surgery, and Medicine”. Each one of the 77 journals selected was analyzed using the Cited Reference Search tool of the ISI Web of Science database to identify the most cited articles up to June 2012. The following information was gathered from each article: names and number of authors, journal, year of publication, type of study, methodological design, and area of research.

Results

The number of citations of the 100 selected articles varied from 326 to 2050. All articles were published in 21 of 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 (18 articles), and the Journal of Dental Research (16 articles). There was a predominance of clinical research (66 %) over basic research (34 %). The most frequently named author was Socransky SS, with 9 of the top 100 articles, followed by Lindhe J with 7. The decades with most articles published of the 100 selected were 1980–1989 (26 articles) and 1990–1999 (25 articles). The most common type of article was the case series (22 %), followed by the narrative review/expert opinion (19 %). The most common area of study was periodontology (43 % of articles).

Conclusions

To our knowledge, this is the first report of the top-cited articles in Dentistry. There is a predominance of clinical studies, particularly case series and narrative reviews/expert opinions, despite their low-evidence level. The focus of the articles has mainly been on periodontology and implantology, and the majority has been published in the highest impact factor dental journals.

Clinical significance

The number of citations that an article receives does not necessarily reflect the quality of the research, but the present study gives some clues to the topics and authors contributing to major advances in Dentistry.     

The periodontal pocket

Periodontal disease is synonymous with the presence of periodontal pockets, and very often the clinical success of periodontal therapy is based on periodontal pocket depth reduction. Therefore, in the fields of periodontology and implant dentistry, significant research effort has been placed on the etiopathogenesis, diagnosis and treatment of periodontal/peri‐implant disease and as a consequence on pocket pathology. In this volume of Periodontology 2000, the in‐depth reviews include topics ranging from preclinical models, anatomy and structure of tissues, and molecular and bacterial components, to treatments of pockets around teeth and implants. These reviews aim to provide the readers with current and future perspectives on the different areas of research into the periodontal pocket.     

Modern implant dentistry based on osseointegration: 50 years of progress,current trends and open questions

In the 1960s and 1970s, implant‐supported prostheses based on subperiosteal or blade implants had a poor reputation because of questionable clinical outcomes and lack of scientific documentation. The change to a scientifically sound discipline was initiated by the two scientific pioneers of modern implant dentistry, Professor P. I. Brånemark from the University of Gothenburg in Sweden and Professor André Schroeder from the University of Bern in Switzerland. Together with their teams, and independently of each other, they laid the foundation for the most significant development and paradigm shift in dental medicine. The present volume of Periodontology 2000 celebrates 50 years of osseointegration. It reviews the progress of implant therapy over the past 50 years, including the basics of implant surgery required to achieve osseointegration on a predictable basis and evolving innovations. The development of bone‐augmentation techniques, such as guided bone regeneration and sinus floor elevation, to correct local bone defects at potential implant sites has increased the indications for implant therapy. The paradigm shift to moderately rough implant surfaces resulted in faster and enhanced bone integration and led to improvements in various treatment protocols, such as immediate and early implant placement in postextraction sites, and made various loading protocols possible, including immediate and early implant loading. In the past 15 years, preoperative analysis and presurgical planning improved as a result of the introduction of three‐dimensional imaging techniques. Hereby, cone‐beam computed tomography offers better image quality with reduced radiation exposure, when compared with dental computed tomography. This opened the door for digital planning and surgical modifications. Over the last 50 years this evolution has facilitated tremendous progress in esthetic outcomes with implant‐supported prostheses and improved patient‐centered outcomes. This volume of Periodontology 2000 also discusses the current trends and open questions of implant dentistry, such as the potential of digital implant dentistry in the surgical and prosthetic field, the trend for an increasing average age of implant patients and the related adaptations of treatment protocols, and the second attempt to establish ceramic implants using, this time, zirconia as the implant material. Finally, some of the hottest controversies are discussed, such as recent suggestions on bone integration being a potential foreign‐body reaction and the evidence‐based appraisal of the peri‐implantitis debate.     

THE EVOLUTION OF THE JOURNAL OF APPLIED ORAL SCIENCE: A BIBLIOMETRIC ANALYSIS

The purpose of this study was to make a brief diagnosis of the evolution of the Journal of Applied Oral Science (JAOS) between 2005 and 2007, by reviewing quantitative and qualitative aspects of the articles published in the JAOS within this period. All articles published in the JAOS in the time span established for this survey were analyzed retrospectively and a discussion was undertaken on the data referring to the main bibliometric indexes of production, authorship, bibliographic sources of the published articles, and the most frequently cited scientific journals in the main dental research fields. A total of 247 papers authored and coauthored by 1,139 contributors were reviewed, most of them being original research articles. The number of authors per article was 4.61 on the average. Regarding the geographic distribution, the authors represented almost all of the Brazilian States. Most published articles belonged to the following dental research fields: Endodontics, Restorative Dentistry, Dental Materials and Prosthodontics. The ranking of the most frequently cited scientific journals included the most reputable publications in these dental research fields. In conclusion, between 2005 and 2007, the JAOS either maintained or improved considerably its bibliometric indexes. The analysis of the data retrieved in this study allowed evaluating the journal''s current management strategies, and identifying important issues that will help outlining the future directions for the internationalization of this journal.     

Food Impaction and Periodontal/Peri‐Implant Tissue Conditions in Relation to the Embrasure Dimensions Between Implant‐Supported Fixed Dental Prostheses and Adjacent Teeth: A Cross‐Sectional Study

Background: Food impaction and periodontal/peri‐implant tissue conditions were evaluated in relation to the embrasure dimensions between implant‐supported fixed dental prostheses (FDPs) and adjacent teeth. Methods: A total of 215 embrasures of 150 FDPs in 100 patients (55 males and 45 females, aged 27 to 83 years; mean age: 56 years) were included in the study. Clinical assessments of the periodontal/peri‐implant mucosal conditions, radiographic assessments of embrasure dimensions, and overall patient satisfaction were used as explanatory variables for the food impaction and periodontal/peri‐implant tissue conditions adjacent to implant‐supported FDPs in the generalized estimating equation (GEE) analysis. Results: Food impaction was reported in 96 (44.7%) of 215 embrasures between implant‐supported FDPs and adjacent teeth. Food impaction was reported more frequently in the embrasures with proximal contact loss than in those with tight contact (P = 0.009). Overall patient satisfaction was influenced negatively by food impaction in the proximal embrasures (P = 0.01). Among embrasure dimensions, only the embrasure surface area (ESA) significantly influenced food impaction (P = 0.03). Significant influences of various embrasure dimensions on the periodontal/peri‐implant mucosal conditions and bone level at the implant were found in the univariate and multivariate GEE analyses. Conclusions: Food impaction between implant‐supported FDPs and adjacent teeth occurred more frequently when proximal contact was lost and ESA increased. Food impaction negatively affected overall patient satisfaction. Embrasure dimensions influenced the periodontal/peri‐implant mucosal conditions and bone level at the implant.     

Clinical follow-up of unilateral, fixed dental prosthesis on maxillary implants

Aims/Background: The aims of the present study were to evaluate (1) the success rate of unilateral maxillary fixed dental prosthesis (FDPs) on implants in patients at a periodontal clinic referred for periodontal treatment, (2) the prevalence of varying mechanical and biological complications and (3) effects of potential risk factors on the success rate. Material and methods: Fifty consecutive patients were invited to participate in a follow‐up. The patients had received FDPs on implants between November 2000 and December 2003 after treatment to achieve optimal peridontal health, and the FDPs had been in function for at least 3 years. A questionnaire was sent to the patients before the follow‐up examination. Forty‐six patients with 116 implants were examined. The follow‐up comprised clinical and radiographic examinations and evaluations of treatment outcome. Results: Before implant treatment, 13% of the teeth were extracted; of these, 80% were extracted due to periodontal disease. No implants had been lost before implant loading. One implant in one patient fractured after 3 years of functional loading and three implants in another patient after 6.5 years. The most frequent mechanical complications were veneer fractures and loose bridge screws. Patients with peri‐implant mucositis had significantly more bleeding on probing around teeth and implants. Patients with peri‐implantitis at the follow‐up had more deep periodontal pockets around their remaining teeth compared with individuals without peri‐implantitis, but these differences were not significant. Smokers had significantly fewer teeth, more periodontal pockets ≥4 mm and a tendency towards greater marginal bone loss at the follow‐up, compared with non‐smokers. Conclusion: In the short term, overloading and bruxism seem more hazardous for implant treatment, compared with a history of periodontitis. To cite this article:
Wahlström M, Sagulin G‐B, Jansson LE. Clinical follow‐up of unilateral, fixed dental prosthesis on maxillary implants
Clin. Oral Impl. Res. 21 , 2010; 1294–1300.
doi: 10.1111/j.1600‐0501.2010.01948.x     

Does tooth brushing influence the development and progression of non‐inflammatory gingival recession? A systematic review

Aim: The aim of this systematic review was to produce the best available evidence and pool appropriate data to evaluate the effect of tooth brushing on the initiation and progression of non‐inflammatory gingival recession. Material and Methods: A protocol was developed a priori for the question: “Do factors associated with tooth brushing predict the development and progression of non‐inflammatory gingival recession in adults?” The search covered six electronic databases between January 1966 and July 2005. Hand searching included searches of the Journal of Clinical Periodontology, Journal of Periodontal Research and the Journal of Periodontology. Bibliographies of narrative reviews, conference proceedings and relevant texts known to the authors were also searched. Inclusion of titles, abstracts and ultimately full texts was based on consensus between three reviewers. Results: The full texts of 29 papers were read and 18 texts were eligible for inclusion. One abstract from EuroPerio 5 reported a randomized‐controlled clinical trial [Level I evidence] in which the authors concluded that the toothbrushes significantly reduced recessions on buccal tooth surfaces over 18 months. Of the remaining 17 observational studies, two concluded that there appeared to be no relationship between tooth brushing frequency and gingival recession. Eight studies reported a positive association between tooth brushing frequency and recession. Other potential risk factors were duration of tooth brushing, brushing force, frequency of changing the toothbrush, brush (bristle) hardness and tooth brushing technique. None of the observational studies satisfied all the specified criteria for quality appraisal and a valid appraisal of the quality of the randomized‐controlled trial was not possible. Conclusion: The data to support or refute the association between tooth brushing and gingival recession are inconclusive.     

The clinical success of tooth‐ and implant‐supported zirconia‐based fixed dental prostheses. A systematic review

The aim was to make an inventory of the current literature on the clinical performance of tooth‐ or implant‐supported zirconia‐based FDPs and analyse and discuss any complications. Electronic databases, PubMed.gov, Cochrane Library and Science Direct, were searched for original studies reporting on the clinical performance of tooth‐ or implant‐supported zirconia‐based FDPs. The electronic search was complemented by manual searches of the bibliographies of all retrieved full‐text articles and reviews, as well as a hand search of the following journals: International Journal of Prosthodontics, Journal of Oral Rehabilitation, International Journal of Oral & Maxillofacial Implants and Clinical Oral Implants Research. The search yielded 4253 titles. Sixty‐eight potentially relevant full‐text articles were retrieved. After applying pre‐established criteria, 27 studies were included. Twenty‐three studies reported on tooth‐supported and 4 on implant‐supported FDPs. Five of the studies were randomised, comparing Y‐TZP‐based restorations with metal–ceramic or other all‐ceramic restorations. Most tooth‐supported FDPs were FDPs of 3–5 units, whereas most implant‐supported FDPs were full arch. The majority of the studies reported on 3‐ to 5‐year follow‐up. Life table analysis revealed cumulative 5‐year survival rates of 93·5% for tooth‐supported and 100% for implant‐supported FDPs. For tooth‐supported FDPs, the most common reasons for failure were veneering material fractures, framework fractures and caries. Cumulative 5‐year complication rates were 27·6% and 30·5% for tooth‐ and implant‐supported FDPs, respectively. The most common complications were veneering material fractures for tooth‐ as well as implant‐supported FDPs. Loss of retention occurred more frequently in FDPs luted with zinc phosphate or glass–ionomer cement compared to those luted with resin cements. The results suggest that the 5‐year survival rate is excellent for implant‐supported zirconia‐based FDPs, despite the incidence of complications, and acceptable for tooth‐supported zirconia‐based FDPs. These results are, however, based on a relatively small number of studies, especially for the implant‐supported FDPs. The vast majority of the studies are not controlled clinical trials and have limited follow‐up. Thus, interpretation of the results should be made with caution. Well‐designed studies with large patient groups and long follow‐up times are needed before general recommendations for the use of zirconia‐based restorations can be provided.     

Bibliometrics Study on Authorship Trends in Periodontal Literature From 1995 to 2010

Background: Biomedical research has grown considerably in the last few decades, and the authorship characteristics of the dental literature as a whole and of its specialty fields has changed significantly. Unfortunately, the bibliometrics of the periodontal literature have not been thoroughly investigated. The aim of this study is to investigate the bibliometrics of periodontal literature, assessing the geographic origin, study design, and topics investigated in periodontal research published from 1995 to 2010. Methods: Articles published in periodontal journals during 1995 to 2010 were retrieved through hand search. Inclusion/exclusion criteria were applied. The following variables were extrapolated from each article: number of authors, study design, topic investigated, financial support, and geographic origin. The general linear model assessed the influence of independent variables on number of authors per article, and χ² test assessed the statistical difference of the variables over years 1995 to 2010. Results: A total of 2,260 articles were reviewed; 2,076 met the inclusion criteria. The number of authors per article increased (P <0.001) from 4.0 (1995) to 5.1 (2010). The proportion of articles published from North America and Europe decreased (P <0.001) from 84.3% (1995) to 58.6% (2010), whereas for Asia and South America the article proportion increased (P <0.001) from 13.8% (1995) to 40% (2010). Research targeting prevention and treatment of periodontal disease is decreasing (P <0.001) in favor of implant‐related research. Governmental research funding is increasing (P <0.001). Conclusion: Periodontal research significantly changed during the last 15 years.     

Nonsurgical therapy for teeth and implants—When and why?

As periodontal and peri‐implant diseases represent opportunistic infections, antiinfective therapy is the method of choice. Correctly performed, the treatment outcomes will include resolution of the inflammation concomitant with shrinkage of the tissues, reflected in reduced probing depths. Depending on the patient data obtained after initial antiinfective therapy, further – mostly surgical – treatment may be rendered to reach the goals of a healthy periodontium and peri‐implant tissues. Patient compliance is as important as operator skills for optimal treatment outcomes. Regenerative therapy may be applied in compliant patients and for appropriate defects. This article depicts the historical development of periodontal therapy during the 20th century and addresses the various outcome parameters to be used in daily decision making. Obviously, nonsurgical therapy has gained clinical relevance, resulting in highly satisfactory treatment outcomes in many cases. The critical probing depth above which positive attachment gain is registered varies from one treatment modality to another. It is a concept that helps facilitate decision making for additional therapeutic measures after initial therapy. Treatment of peri‐implant mucositis prevents development of peri‐implantitis. Hence, nonsurgical treatment of mucositis is frequently performed during the continuous monitoring of oral implants. This chapter of Periodontology 2000 presents evidence for the prevention and therapy of peri‐implant diseases.     

Orthodontic literature: an overview of the last 2 decades.

The aim of this study was to explore the orthodontic literature in the most important orthodontic and other dental and medical journals from 1981 to 2000. The most commonly used medical bibliographic database, MEDLINE, was used. In addition, some journals were hand searched to estimate the error of the method. Despite some indexing inconsistencies, MEDLINE was found to be a powerful and relatively accurate tool for use in bibliometric studies. About 16,000 articles with orthodontic interest were published during this period. The number of orthodontic articles written in English rose during this period, but almost half of them (45%) were published in nonorthodontic journals. Articles in the orthodontic journals are focusing more and more on diagnosis and treatment evaluation as the need for high-quality evidence becomes obvious, while other topics, such as new techniques and new materials, are losing ground. Many high-quality studies with orthodontic interest are published in nonorthodontic journals with a high Impact Factor, remaining more or less out of reach for most orthodontists.     

Microbiota around teeth and dental implants in periodontally healthy,partially edentulous patients: is pre‐implant microbiological testing relevant?

Meijndert L, van der Reijden WA, Raghoebar GM, Meijer HJA, Vissink A. Microbiota around teeth and dental implants in periodontally healthy, partially edentulous patients: is pre‐implant microbiological testing relevant? Eur J Oral Sci 2010; 118: 357–363. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci This study aimed to assess the prevalence of seven periodontal marker pathogens, before implant placement and 1 yr after loading, in periodontally healthy individuals and to assess the long‐term effectiveness of pre‐implant reduction of pathogens to below threshold levels. In 93 individuals needing single tooth replacement, pooled subgingival microbiological samples from standard sites were cultured and analyzed before implant treatment and 1 yr after loading. Threshold levels commonly used in periodontology to predict periodontal breakdown were applied. Subjects with levels of pathogens above these thresholds received initial periodontal treatment including systemic antibiotics when indicated. At baseline, 49.5% of periodontally healthy subjects harboured one or more marker pathogens above threshold levels. Periodontal treatment reduced the pathogen levels below threshold values in 78.3% of these initially colonized subjects. In all cases Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were reduced to below threshold. At 1 yr after loading, periodontal pathogens were present above threshold levels in 74.1% of all subjects. It is concluded that in almost half of periodontal healthy individuals the subgingival biofilm harbours periodontal pathogens above threshold values. Long‐term effectiveness of pre‐implant reduction of the selected marker pathogens appeared limited in our patient population, making pre‐implant reduction unpredictive for post‐implant levels of these pathogens. Thus, considering the applied microbiological criteria, generalized pre‐implant microbiological testing is not contributory in periodontally healthy subjects.     

Treatment trends in periodontics

This volume of Periodontology 2000, entitled “Treatment Trends in Periodontics”, evaluates the importance of nonsurgical periodontal therapy and defines its role as the key etiologic treatment of the disease. The need for scaling and root planing is mandatory step during the initial phase of therapy, as is self‐care by the patient. Only after reevaluation of the outcome achieved by nonsurgical procedures should surgery be considered, and the concept of “critical probing depth” is emphasized. The chapters in this volume discuss different aspects of periodontal surgery, including regeneration and plastic periodontal procedures, and, looking toward the future, cell therapy in periodontics is explored. The impact of periodontal therapy on systemic diseases is reviewed, and the role of occlusion in periodontal disease is revisited and discussed. Topics on implants include their placement in fresh extraction sockets, socket healing with or without implant placement, and research on osseointegration. The important topic of maintenance care of teeth and implants for long‐term therapeutic success is thoroughly evaluated, as is the efficacy of dentifrices in oral hygiene. The editors convey a nutshell review of the concepts of what periodontal treatment should entail, based on scientific evidence generated during half‐a‐century of work in periodontics.