The 100 Most Cited Publications on Dental Ceramics between 1980 To 2020: A Bibliometric Analysis
Correspondence Address :
Dr. Sheetal Jadhav,
TPCT’s Terna Dental College, Plot No. 12, Sector-22, Opp. Nerul West Railway Station,
Nerul West, Navi Mumbai-400706, Maharashtra, India.
E-mail: sheetaljadhav96@gmail.com
Introduction: Evidence-based dentistry provides clinically oriented decisions with the help of available scientific data and literature. The significance of an article is reflected by its citation count, the impact it has on clinical practice. This is where bibliometric studies play an important role by providing an overview of research and scientific activity by calculating bibliometric indicators that give information about the quantity of published research in a specific field. The citation index is considered an important parameter for measuring relevance in a specific field. Articles that are heavily cited are considered important in the field of dental ceramics as they can provide basic information, recent advances, and the areas that are extensively researched.
Aim: To perform a bibliometric analysis of the 100 most cited publications in the field of dental ceramics, in the past 40 years from 1980-2020.
Materials and Methods: The Scopus database was used to retrieve all publications with titles containing the term “Dental Ceramics”. Thereafter, the data obtained was arranged in a descending order and a list of the 100 most cited publications were prepared. The data was analysed for the number of citations, the journals in which they were published, its impact factor, the work of the author, country in which it was published, document type retrieved, university affiliation, funding sponsors, area of subject in study, and the number of articles published per year. Prediction of future growth trend was also analysed using data gathered in Microsoft Excel software.
Results: Out of the retrieved data, 3815 was the highest number of citations recorded. Two of the articles received more than 1000 citations and 32 articles were cited less than 100 times. These 100 publications were documented from the year 1986-2018. Largest number of publications were made in the Journal of Dental Materials (n=31), followed by the Journal of Prosthetic Dentistry (n=12) and Journal of Dental Research (n=10). 85 of the total documents were original articles, 12 were reviews, two cited publications were books and one was a conference paper.
Conclusion: The bibliometric analysis of the 100 most cited articles revealed a marked change in the trends and progress that has taken place in the field of dental ceramics amongst the researchers, clinicians and technicians.
Bibliographies, Dental Material, Growth Trend, Statistical Bibliographies
Evidence-based dentistry provides clinically oriented decisions with the help of available scientific data and literature. Publication of papers in scientific journals is the most commonly used strategy to promulgate research findings. The published literature is extensive and although easily accessible, clinicians, researchers as well as technicians cannot always gauge the quality of the publications they read. Furthermore, the areas in which the research has been made shows dramatic progress that may be difficult to identify. Research in this field has increased largely because of increasing esthetic demands amongst patients and scientific knowledge regarding clinical procedures and equipment amongst the researchers, clinicians and technicians. The significance of an article is reflected by its citation count, the impact it has on clinical practice and the discussions it generates which triggers research in new directions. Citations are potential markers of a paper's influence in this growing scientific research arena. This is where Bibliometric studies play an important role by providing an overview of research and scientific activity by calculating bibliometric indicators that give information about the quantity of published research in a specific field. The citation index is considered an important parameter for measuring relevance in a specific field (1),(2). Articles that are heavily cited are considered important in the field of dental ceramics as they can provide basic information, recent advances, and the areas that are extensively researched. Also they can predict the future direction of the research field (3).
Eugene Garfield introduced the term citation classic in 1955 to identify the top cited scientific articles in the Institute for Scientific Information (ISI) Web of Knowledge now known as the Web of Science database (4). Most of the literature can be assessed from different databases like Google Scholar, PubMed, Scopus, and Web of Science. Similarly, in the field of Medicine, National Library of Medicine (NLM) in United States was introduced in 1971 and later on in 1997, PubMed was launched by combining the ‘Old Medline’ and ‘Medline’ databases. PubMed is widely used and most reliable database for clinical and research purposes (5).
Citation analysis of a particular paper determines the number of times a research paper has been cited by other authors. It imparts knowledge about the ongoing research and the importance of the topic in a particular field. Bibliometric analysis is a quantitative science, applying mathematical and statistical methods like citation analysis, to gauge the performance of a research article (6). Bibliometrics contributes to the citation-based metrics like Journal impact factor, H-index, Citation classics to quantify the impact of a particular journal or a paper or an individual (6).
H-index was introduced by Hirsch, which is used as a tool for evaluating the scientific work of a researcher and can be defined as: A scientist has index h if h of his or her Np (number of papers) have minimum of h citations each, and the other (Np-h) papers have ≤ h citations each (6). Besides determining the scientific career of a researcher the use of H-index can be extended to evaluate the impact of the journal, contribution of scientific institutions and countries in the field of research. H-classic is based on the concept of H-index, which considers both the number of papers published and their impact on the scientific field (7). H-classic provides a more reliable scientific method to determine the citation classic. The classic papers identified provides the basic knowledge in a particular field that will then help to develop the concepts and understanding of the topic in a better way among the clinicians. It provides information on the most researched topic and the contribution of top researchers in that discipline (7).
Bibliometric studies provide academic knowledge and development in various fields. Eugene Garfield first performed a study in 1987 to identify the 100 citation classic articles in the field of medicine in the Journal of the American Medical Association (8). Extensive bibliometric studies have been undertaken in fields of biomedical research to analyse the highly cited articles, in different fields of dentistry like Orthodontics, Endodontics, Oral and Maxillofacial Surgery, Pedodontics and Periodontics, General Dentistry, Implant Dentistry (1),(9),(10),(11),(12),(13),(14),(15),(16),(17). Although, not many Bibliometric studies have been undertaken in the field of Prosthodontics, Fardi A et al., published an article describing top cited articles in the field of Implant Dentistry in 2017 (13). Recently in 2020, Gadde P et al., published an article on the 100 most cited articles in prosthodontic journals from the year 1980 to 2019 (17).
The first ever scientific laboratory experiments on ceramic material were carried out in the year 1708 which became the basis for Pierre Fauchard to introduce the modern day ceramics in dentistry in 1728. In 1903, Charles H Land introduced the first ceramic crowns in the field of dentistry and since then a prodigious amount of development has taken place in this field, in terms of manufacturing processes, the composition of the material used as well as its wide range of applications to rehabilitate as well as re-design the human dentition (18),(19). Dental ceramics are a material used for fabricating highly esthetic lifelike restorations which justifies the need for extensive research being carried out on this topic (20). Thus, this study aimed to analyse the characteristics of the 100 most cited publications in the field of dental ceramics, from the year 1980-2020 to reveal valuable and interesting information about scientific advancements, evolution and also highlight the current trends in this field.
Bibliometeric analysis is an electronic search that describes the patterns of publication. An electronic search was carried out on 20th July 2020. There was no restriction applied for the study process. Search was carried out in Scopus database. All the articles published from July 1980-July 2020 were selected for the study. A total of 1714 publications were retrieved from Science Citation Index- Expanded Tool from Scopus Database. The documents were searched using ‘Dental Ceramics’ as the keyword. A search was performed in July 2020 using the Scopus database. All the literature published from 1980-2020 were included in the study. Articles published in different languages were excluded.
This provided a citation count ranking of all the literature thus gathered. Later, the resulting list was sorted by the number of citations in descending order. Two researchers (JS, SP) performed paper selection and data extraction. The title and abstracts were reviewed to assure the relevance of the topic. Any disagreement on data extraction was resolved through discussion and consensus of all the authors. The assessment stopped at the 100th most cited paper. The documents retrieved were analysed for the number of citations, and also, the authors were analysed according to their work. No restriction on the type of journal was applied. The journal in which they were published and the impact factor for each was recorded along with the H-index and quartile was obtained from Scimago Journal and Country Rank. The following information was extracted for each paper: the country of publication, the type of documents retrieved, affiliations of the authors to the university, and the funding sponsors were also assessed. The area of the subject in the study and the number of articles published per year was also taken into consideration. Using the currently available data the future growth trend was predicted with the help of Microsoft Excel software.
Statistical Analysis
The data was retrieved from Scopus database directly that was downloaded in Microsoft Excel software. Further the data was grouped according into different categories depending on its source of retrieval, authors involved, country in which study was conducted, and funding sources if they acquired any.
A total of 1714 documents were retrieved from the following search strategy with H-index of 86. The H-index of the 100 most cited articles thus retrieved was calculated to be 82 after excluding self-citations. The top 100 cited publications in the field of dental ceramics have been arranged in descending order as seen in (Table/Fig 1).
The shortlisted publications included: 85 original articles, 12 reviews, two books, and one conference paper. All the researches included were conducted in the last 32 years from 1986-2018. The number of articles published reached its peak in the year 2004 which accounted for 10% of all the gathered data (Table/Fig 2).
The least number of citations received was 77 and the maximum number went up to 3815. ‘Bioceramics: From Concept to Clinic’ was the title of the article published in 1991 that received the highest number of citations (3815) wherein the author has described the extensive use of Bioceramics which may be bioinert, bioactive resorbable, or porous material for tissue connections (Table/Fig 1) (21). Herein, the author also highlighted that the use of Bioceramics is not just limited to dentistry but can also be used for repair of damaged tissue, orthopaedic surgeries as well as the replacement of maxillofacial and periodontal structures (21). The second highest cited article with 1061 citations which was titled: ‘State of the Art of Zirconia for Dental Application’ was published in the year 2008 (22). The author has emphasised the use and properties of Zirconia in Dentistry. Here the author has described three different types of Zirconia used in dentistry based on their method to undergo transformation toughening, namely, Yttrium cation-doped tetragonal zirconia polycrystals (3Y-TZP), Magnesium Partially Stabilised Zirconia (Mg-PSZ) and Glass infiltrated Zirconia-Toughened Alumina (ZTA). The author has extensively discussed Zirconia and its varied applications as it has excellent mechanical and esthetic properties and is widely used worldwide for the restoration of posterior teeth (22).
These top cited articles were published in 27 different journals. The majority of the studies were published in the Dental Material journal (n=31) followed by the Journal of Prosthetic Dentistry (n=12) and the Journal of Dental Research (n=10). These three journals alone contributed to more than 50% of published articles (Table/Fig 3). Journal metrics for the distribution of most cited articles can be seen in (Table/Fig 4).
These documents were published by a total of 159 authors, wherein, Anusavice KJ (23),(24),(25),(26),(27),(28),(29),(30),(31),(32) and Kelly JR (22),(33),(34),(35),(36),(37),(38),(39),(40),(41) made the highest contribution of 10 articles, followed by Lawn BR (42),(43),(44),(45),(46),(47),(48),(49),(50) with nine articles and Zhang Y (42),(44),(46),(48),(50),(51),(52) who published seven articles. Swain MV (53),(54),(55),(56),(57),(58) published six articles, whereas Rekow ED (42),(43),(49),(51) published four articles. Thompson VP (24),(42),(43),(49),(51) made contribution of five articles (Table/Fig 5) (22),(23),(24),(25),(26),(27),(28),(29),(30),(31),(32),(33),(34),(35),(36),(37),(38),(39),(41),(43),(44),(45),(46),(47),(48),(49),(50),(51),(52),(53),(54),(55),(56),(57),(58),(59),(60),[61],[62].
The research was carried out in 29 different countries. Among the data analysed most of the studies were carried out in the United States (n=50) followed by Germany (n=14) and Brazil (n=10) and most of the research was being conducted at the National Institute of Standards and Technology (n=13) (Table/Fig 6).
The data analysed from the present study suggests that knowledge and understanding of ceramics is not just confined to dentistry but incorporated a wide variety of study subjects like Dentistry (75), Material Science (55), Engineering (49), Biochemistry, Genetics and Molecular biology, and Chemical Engineering (each 7), Physics and Astronomy (3), Medicine (2), and Chemistry (1).
Eighteen different funding sources were identified that sponsored 38 different researches (Table/Fig 7). Among them, the National Institute of Dental and Craniofacial Research sponsored nine different researches.
The projection of the growth trend as depicted in (Table/Fig 8) has been prepared based on the data collected from the year 1986-2018. According to this a steady rise in the number of publications is seen and by 2040, approximately seven articles per year can be expected to be published.
There has been a tremendous amount of revolution that has occurred over the decades in the various concepts, manufacturing processes, and applications of dental ceramics (18). The bibliometric analysis provides an insight into the development and evolution of dental ceramics with its ever changing concepts and improving properties. It helps in understanding the most explored areas in a particular field as well as highlights the areas which have not been researched as much thus motivating researchers to carry out further studies on those topics. The number of citations received by a particular paper is used to determine its importance in the research field. The citations are collected over a while and the older articles may have received more citations than the recently published data (59). Thus, the time of publication has to be taken into consideration while studying citation analysis. Citation classics can be determined by two methods: (i) Setting citation threshold; (ii) Choosing papers from the list of highly cited articles (6). The citation rates differ among various fields of the specialty, hence, no rigid threshold can be applied to determine the citation classic. If any article has received more than 400 citations in a larger research field or more than 100 in a smaller research field it is considered as “Citation Classic” (4),(6). But there is no scientific basis for determining this and different authors may evaluate their work by creating their standards for determining citation classic (6).
There are three popular databases used for bibliometric analysis- Google Scholar, Scopus and Web of Science. Though Google Scholar is the largest database it does not filter the self-citations of the authors that can alter the citation rates or produce false positive citations. Scopus database covers a wide collection of journals from PubMed and Web of Science (5). It provides more valuable and accurate information for citation analysis. It can be used for both academic as well as research purposes in the medical literature (5).
In the present study, the data was retrieved from the Scopus database, the H-index was calculated to be 82 with the exclusion of self-citation among the 100 retrieved documents. The research was published in 29 different countries and the majority of the studies were executed in the United States (n=50) where most of the leading research centres are located followed by Germany (n=14) and Brazil (n=10). More than 50% of the articles were published in Dental materials journal (n=31), Journal of prosthetic dentistry (n=12), and Journal of dental research (n=10). All three journals are in the first Quartile. The true scientific impact of an article can be determined after at least two decades of its publication. Thus, the article may be cited highly only after 3 to 10 years of its publication (7).
Bradford's Law of Scattering asserts that in a subject field, there are a few journals that are cited more frequently and are thus likely to be of a higher level of interest to researchers in the discipline (60),[61]. Bradford’s law of scattering which is a theorem, can be used to explain the occurrence of majority of articles in the core group of the journal published on a specific subject [62]. Impact factor of the journal is considered as the driving force for the authors to get their papers published in a good journal. Authors generally prefer to publish articles in journals with a high impact factor and a greater Quartile number [62]. Impact factor as of 2019 for the journals are 4.495 for Dental Material, 2.444 for Journal of prosthetic dentistry, and 4.914 for Dental Research, 1.49 for International Journal Of Prosthodontics, 3.47 for Journal Of Dentistry, 10.25 for Biomaterials. Number of articles published in Dental material journal was 31. This explains the relationship between the impact factor of the journal and the higher number of articles published in those journals. According to the data collected the work of all the authors was published from the year 1986-2018 with the highest surge witnessed in 2004 which marked the year with the highest number of articles published. Also, the prediction of growth trend shows that there is a steady rise in the number of publications which thereby depicts the scope for a substantial amount of growth and development in this field.
The bibliometric analysis provides an objective evaluation of the research. Citation count does not give any information on the quality of the content but provides the data regarding the most researched field. The number of citations varies greatly depending upon the year of publication of an article. It does not necessarily reflect the standard of an article, as it tends to accumulate citations over a period which could result in temporal bias, as the older publications tend to accumulate more citations than the recently published articles (13).
Dental ceramics as we know is an extensive topic and hence we have also taken into consideration non dental journals which have elucidated on the topic from a material science perspective. Thus, the data obtained is heterogeneous. Although citation analysis may come with some drawbacks, it still can be beneficial for academic purposes.
Limitation(s)
Inclusion criteria for this study was not defined adequately. Also, no restrictions were applied to the type of publication to be included in the study.
From this bibliometric analysis, it can be concluded that there has been extensive research done to improve the properties of dental ceramics since its introduction to make it successful in long term clinical performance. The basic understanding of these properties enables the clinician to choose from the wide varieties of dental ceramics wisely and prudently under evidence-based dentistry. Also, the growth trend suggests an increase in approximately seven articles per year in the field of dental ceramics by the year 2040. This information will be useful for the aspiring dentists to create a base for their understanding and also motivate various researchers to carry out further research.
The author would like to acknowledge Dr. Sachin Sarode, Professor, Department of Oral Pathology, DY Patil Dental College, Pimpiri, Pune, Maharashtra, India and Dr. Nikhil Bhanushali, Associate Professor, Department of Public Health Dentistry, Terna Dental College, Nerul, Navi Mumbai, Maharashtra, India for their valuable help and guidance.
DOI: 10.7860/JCDR/2022/51342.16149
Date of Submission: Jul 11, 2021
Date of Peer Review: Nov 17, 2021
Date of Acceptance: Jan 20, 2022
Date of Publishing: Apr 01, 2022
AUTHOR DECLARATATION:
• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? NA
• Was informed consent obtained from the subjects involved in the study? NA
• For any images presented appropriate consent has been obtained from the subjects. NA
PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Jul 19, 2021
• Manual Googling: Jan 20, 2022
• iThenticate Software: Jan 25, 2022 (11%)
ETYMOLOGY: Author Origin
- Emerging Sources Citation Index (Web of Science, thomsonreuters)
- Index Copernicus ICV 2017: 134.54
- Academic Search Complete Database
- Directory of Open Access Journals (DOAJ)
- Embase
- EBSCOhost
- Google Scholar
- HINARI Access to Research in Health Programme
- Indian Science Abstracts (ISA)
- Journal seek Database
- Popline (reproductive health literature)
- www.omnimedicalsearch.com