UNIVERSIDADE ESTADUAL PAULISTA
“JÚLIO DE MESQUITA FILHO”
Instituto de Ciência e Tecnologia
Campus de São José dos Campos
ORIGINAL ARTICLE DOI: https://doi.org/10.4322/bds.2023.e3667
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Braz Dent Sci 2023 Jan/Mar.;26 (1): e3667
Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
Impacto da pandemia de COVID-19 na taxa de publicação em periodontia e implantodontia na Turquia
Aliye AKCALI
1,2,3
, Mehmet Selim YILDIZ
4
, Mehmet Emin ARAYICI
5
, Hülya ELLIDOKUZ
6,7
1 - Dokuz Eylul University, Faculty of Dentistry, Department of Periodontology, Izmir, Turkey.
2 - Dokuz Eylul University, Institute of Health Sciences, Department of Dental Biomaterials, Izmir, Turkey.
3 - Queen Mary University of London, Barts and The London School of Medicine & Dentistry, Institute of Dentistry, Centre for Oral
Clinical Research, London, UK.
4 - Altınbas University, Faculty of Dentistry, Department of Periodontology, Istanbul, Turkey.
5 - Dokuz Eylul University, Institute of Health Sciences, Department of Preventive Oncology, Izmir, Turkey.
6 - Dokuz Eylul University, Institute of Oncology, Department of Preventive Oncology, Izmir, Turkey.
7 - Dokuz Eylul University, Faculty of Medicine, Department of Biostatistics and Medical Informatics, Izmir, Turkey.
How to cite: Akcalı A, Yildiz MS, Arayici ME, Ellidokuz H. Impact of the COVID-19 pandemic on publication rate in periodontology and
implantology in Turkey. Braz. Dent. Sci. 2023;26(1):e3667. https://doi.org/10.4322/bds.2023.e3667
ABSTRACT
Objective: The aim of the present study was to evaluate the impact of the COVID-19 pandemic on the number of publications
in the eld of periodontology and implantology in Turkey. Material and Methods: A sensitive search strategy was developed
to identify relevant articles, focusing on the periodontology and implantology research elds published two years before and
after the declaration of the pandemic (March 2020). The search was performed through Web of Science, Medline, SCOPUS and
CENTRAL databases. A three-stage screening (titles, abstract, full-text) was carried out in duplicate and independently by two
reviewers. Results: A total of 382 studies were identied before the pandemic and 307 studies during the pandemic. While
there was a downward trend in the number of observational studies (185 vs 168), the number of clinical trials (CCT/RCT)
slightly increased compared to the pre-pandemic period (72 vs 74). Conclusion: Limited to the selected period of time (two
years) and eld, publication rate on periodontology and implantology in Turkey was decreased during the pandemic. Although
the present research highlights current trends, large-scale investigations are needed to probe consequences of COVID-19
pandemic on research activities in the long-run.
KEYWORDS
COVID-19; Implantology; Periodontology; Publication; Sars-CoV-2; Pandemic.
RESUMO
Objetivo: O objetivo do presente estudo foi avaliar o impacto da pandemia de COVID-19 no número de publicações na área
de periodontia e implantodontia na Turquia. Material e Métodos: Foi desenvolvida uma estratégia de busca sensível para
identicar artigos relevantes, com foco nas áreas de pesquisa em periodontia e implantodontia publicados dois anos antes e
depois da declaração da pandemia (março de 2020). A busca foi realizada nas bases de dados Web of Science, Medline, SCOPUS
e CENTRAL. Uma triagem de três etapas (títulos, resumo, texto completo) foi realizada em duplicata e de forma independente
por dois revisores. Resultados: Foram identicados 382 estudos antes da pandemia e 307 estudos durante a pandemia. Embora
tenha havido uma tendência de queda no número de estudos observacionais (185 vs 168), o número de ensaios clínicos
(CCT/RCT) aumentou ligeiramente em comparação com o período pré-pandêmico (72 vs 74). Conclusão: Limitada ao período
de tempo selecionado (dois anos) e área, a taxa de publicação em periodontia e implantodontia na Turquia diminuiu durante
a pandemia. Embora a presente pesquisa destaque as tendências atuais, são necessárias investigações em larga escala para
investigar as consequências da pandemia de COVID-19 nas atividades de pesquisa a longo prazo.
PALAVRAS-CHAVE
COVID-19; Implantodontia; Periodontologia; Publicação; Sars-CoV-2; Pandemia.
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Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in periodontology and implantology in T urkey
Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
INTRODUCTION
Coronavirus Disease 2019 (COVID-19),
caused by severe acute respiratory syndrome
coronavirus-2 (SARS-CoV-2), had a global inuence
since the beginning of 2020, being declared a
pandemic by the World Health Organization
(WHO) [1]. Since the outbreak of COVID-
19 pandemic, Republic of Turkey, Ministry of
Health as well as Turkish Dental Association have
released guidelines for the best clinical practice and
safety for dental care providers and patients. Briey,
guidelines included disinfection and treatment
protocols, anamnesis and consent forms and safety
recommendations for the patients, dentists and
auxiliary staff [2]. However, there was no restriction
for Nationwide research activities.
The impact of COVID-19 on dentistry has
been evaluated in different aspects including
economical [3], periodontal practice management [4]
and patient perspectives [5]. Likewise, globally,
researchers drew attention to the consequences of
the pandemic on research activities. Accordingly,
they have stated that in addition to travel and
social restrictions, research staff, resources and
research fundings have been mostly allocated to the
the COVID-19 related purposes [6]. Basic science
as well as non-COVID related clinical research
activities such as patient enrollment and data entry
were suspended related to the above mentioned
reasons [7,8]. Due to the suspension of routine
works of universities, research centers and even
private practices, researchers had faced difculties
in conducting their research or continuing their
planned work-flows that is required to publish
their data [9]. Rapid dissemination of data is an
important concern for the research community as
well. Therefore, we have formulated the research
question: Has the COVID-19 pandemic presented
an academic challenge in terms of publication rate
for Nationwide researchers? The aim of the present
study was to evaluate the impact of the COVID-
19 pandemic on the number of publications two
years before and during the pandemic, considering
March 2020 as a reference date in the field of
periodontology and implantology in Turkey.
MATERIAL AND METHODS
Focused question
In the present research, the following
question was addressed:
Is there a difference between publication
rate before and during the COVID-19 pandemic
outbreak?
Inclusion criteria
Considering the hierarchy of evidence,
systematic reviews or/and meta-analyses,
randomized controlled clinical trials/prospective
controlled clinical trials (CCTs), cohort studies,
observational studies, case series, case reports
as well as editorial letters and opinion articles
were included.
Exclusion criteria
In vitro studies and pre-clinical studies were
excluded.
Data sources and search strategy
A structured literature search was
conducted between 16.03.2018 - 12.03.2020 and
12.03.2020 - 07.03.2022 in Web of Science
(WoS), Pubmed / Medline, SCOPUS and
Cochrane Library databases. The following
keywords were selected for the database search:
“
periimplantitis
”, “
peri-implantitis
”, “
periimplant
disease
”, “
peri-implant disease
”, “
periodontology
”,
“
periodontal therapy
”, “
periodontal treatment
”,
“
dental implants
”, “
implantology
”, “
periodontal
regeneration
”, “
guided tissue regeneration
”,
“
guided bone regeneration
”, “
periodontal
disease
”, “
intrabony defects
”, “
infrabony defects
”,
“
periodontitis
”, “
gingivitis
”. The final search
strategy is determined by the characteristics of
each particular database in order to obtain as
many suitable results as possible (Table S1).
Study selection and data extraction
All data for the relevant years were exported
in text or BibTeX format from separately searched
databases and duplicated articles were separated
in the Mendeley program. Available bibliographic
features of all selected articles, such as authors’
names and links, publication year, abstract,
publication name, document type, language,
keywords or DOI, were automatically extracted
by the author MEA and saved in a custom-created
spreadsheet (Microsoft Excel).
Data were extracted according to the
article type, research category and geographical
distribution (affiliation of the corresponding
article was accepted) of articles between the
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Impact of the COVID-19 pandemic on publication rate in periodontology and implantology in T urkey
Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
defined periods. The selection of the studies
included in the present analysis was decided by
two independent experienced periodontists (MSY
and AA) who scanned the titles, abstracts and
full texts of all articles identied in the electronic
literature review. Any disagreement was solved
through discussion, if not resolved a third review
author was consulted (HE). In case of missing or
incomplete data (two weeks’ response time was
set) and absence of further clarication by study
authors the study was excluded from the analysis.
Studies that did not meet the inclusion criteria
were excluded from the analysis as well. Author
MEA performed the subsequent analysis of the
articles three times in order to ensure the validity
and reliability of the study. Analyses were cross-
checked by two authors (MSY and HE). VOSviewer
software version 1.6.18 was used to visualize data,
cluster and dene reference networks, as well as
create bibliometric maps [10].
RESULTS
In the present study, between the
periods 16.03.2018 and 12.03.2020 (before
the pandemic), we reached 10,284 (WoS),
20,429 (SCOPUS), 8,456 (Pubmed/Medline)
and 4,556 (Cochrane Library) records from
the searched databases. Following removal of
duplicate articles, a total of 382 studies were
identified published from Turkey. Between
12.03.2020 and 07.03.2022 (after pandemic),
from the relevant databases; 11,654 (WoS),
18,583 (SCOPUS), 10,045 (Pubmed / Medline)
and 2,972 (Cochrane Library) published articles
were reached. The total number of studies
published in Turkey between selected dates was
307. The ow chart for the selection process of
the articles is provided in Figure 1. Distribution of
the studies according to the selected period and
article type published in the relevant databases
are shown in Table I and Table II.
Among the 382 studies published in Turkey
between the period 2018-2020, 72 were clinical
trials (CCT/RCT), 45 were reviews/systematic
reviews/meta-analyses, 185 were observational
studies and 39 were case reports. Among
307 studies published between 2020-2022,
74 were clinical trials (CCT/RCT), 22 were
reviews/systematic reviews/meta-analyses,
168 were observational studies, and 20 were
case reports. The distribution of the study type by
years is shown in Table II. Compared to the pre-
pandemic period, there was a trend of decrease
in the number of clinical trials and case reports
in the post-pandemic period. On the other hand,
an increase was observed in observational study
category (cohort or case-control studies).
From the analyzed data set, a total number of
2809 authors were identied from the published
articles before the pandemic and 2688 authors after
Figure 1 - Flow diagram of the study search and identification. n = number of studies.
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Impact of the COVID-19 pandemic on publication rate in
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the pandemic. The frequency and surnames of the
authors by years are visualized in Figure 2 (2018-
2020) and in Figure 3 (2020-2022). In the titles
and abstracts of the manuscripts, 7582 Keyword
Plus was determined in the pre-pandemic period
and 7525 in the post-pandemic period. The most
frequently used 10 keywords by the authors were
determined as: “
uid
”, “
model
”, “
canal
”, “
analyzing
subgingival plaque
”, “
loss
”, “
bioactive hybrid
material
”, “
bone implant contact
”, “
biochemical
efficacy
”, “
bone implant connection
”, “
bifid
mandibular canals
”. Overview of the authors’
keywords describing their dental research,
related vocabulary areas, and their frequency of
occurrence presented in Figure 4 and Figure 5.
Study characteristics
Additional details pertaining to design
of clinical trial, intervention type limited to
periodontal treatment, setting, funding and study
population are presented in Table III. Among
72 studies published before pandemic, all studies
were conducted in universities, whereas 5 studies
out of 74 studies were performed in private
practice setting during the pandemic. Origin of
funding were mostly obtained from universities
within the selected dates. The number of studies
comparing both non-surgical and surgical
treatment modalities were approximated before
and during the pandemic. The number of
randomized controlled clinical trials were
increased by 7 studies during the pandemic.
DISCUSSION
During the last few years the COVID-
19 pandemic has been the most important event
of both the scientific community and general
population. The WHO on March 2020 declared
COVID-19 as a pandemic. The present study
aimed to compare differences in the number of
publications before and during the pandemic
considering March 2020 as a reference date.
A decline trend was observed in the number
of studies published in pandemic compared
to the pre-pandemic period. Among the study
types only clinical trials had a trend of slight
increase in the field of periodontology and
implantology in Turkey. To evaluate the impact of
the COVID-19 pandemic on periodontal practice,
a questionnaire based study has been performed
in United States and Brasil [11]. Accordingly,
the enrolled 254 periodontists working in both
private and academic environments described a
negative impact of pandemic on mostly nancial
aspect as well as increased protective measures.
Likewise, economical impact of the pandemic on
Table I - Distribution of articles published in different databases
before and during pandemic
Database
2018-2020
(n=8.456)
2020-2022
(n=10.045)
Pubmed / Medline
Review, Systematic Review, and
Meta-analysis, n
1627 2165
Clinical Trials, n 577 544
Observational study, n 89 76
Case reports, n 495 535
Editorial, n 33 46
Other, n 5635 6679
Database
2018-2020
(n=10.284)
2020-2022
(n=11.654)
Web of Science
Review, Systematic Review, and Meta-
analysis, n
2249 2468
Clinical Trials, n 1087 1175
Observational study, n 160 228
Case reports, n 841 911
Editorial, n 186 58
Other, n 5781 6814
Database
2018-2020
(n=21.429)
2020-2022
(n=18.583)
SCOPUS
Review, Systematic Review, and Meta-
analysis, n
3592 3585
Clinical Trials, n 1834 1656
Observational study, n 911 946
Case reports, n 1597 1308
Editorial, n 186 147
Other, n 13858 11502
Database
2018-2020
(n=4.556)
2020-2022
(n=2.972)
Cochrane Library
Clinical Trials, n 4556 2972
n = number of articles.
Table II - Distribution of study types published before and during
pandemic
Type of study
2018-2020
(n=382)
2020-2022
(n=307)
Review, Systematic Review, and
Meta-analysis, n (%)
45 (12) 22 (7)
Clinical Trials, n (%) 72 (19) 74 (24)
Observational study (Cohort, Case-control),
n (%)
185 (48) 168 (55)
Case reports, n (%) 39 (10) 20 (7)
Other, n (%) 41 (11) 23 (7)
n = number of articles.
Table III - Study characteristics of included clinical trials
2018-2020
(n=72)
2020-2022
(n=74)
Study design (CCT/RCT), n 28/44 23/51
Intervention type (Surgical/Non-Surgical
Periodontal treatment), n
33/39 36/38
Setting (University/Private), n 72/0 69/5
Funding (University/Company/Self-funded), n 38/4/30 50/2/22
Included patients (total number), n 2664 2928
n = number of articles.
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Impact of the COVID-19 pandemic on publication rate in periodontology and implantology in T urkey
Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
Figure 2 - Authors and frequencies of studies published before the pandemic.
Figure 3 - Authors and frequencies of studies published during the pandemic.
Figure 4 - Keywords and frequencies of studies published before the pandemic.
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Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
dental practices in Germany has been modelled
and analyzed recently and remarkable nancial
stresses/pressure on dental practices with
nancial constaints has been reported [3]. Based
on a questionnaire survey, data obtained from
periodontists practicing in United Kindom were
in line with reported nancial concerns as well as
quality of dental services [4]. All those concerns
and limitations also likely had an inuence on
research activities. Still it is hard to measure
challenges in healthcare research occurring
during the pandemic period due to the differences
in government based restrictions (self isolations,
lockdowns), regulations, individual attitute and
behaviours (hesitations to be in contact with
people) [12].
Based on the present data there was a
remarkable downside in the number of publications
in the eld of periodontology and implantology.
Considering research category, while the number
of clinical trials almost similar, the trend was
downward in observational trials. This decrease
could be interpreted as a possible shift in research
grant on COVID-19 related areas. Although the
scientic publication speed of COVID-19 related
topics seem to be reduced [13] excess numbers
of submissions on COVID-19 with a low level of
evidence limits other research elds [14]. Present
descriptive data did not evaluate quality and
missing data (missing visits) which are important
issues to record. Therefore, it is not possible to
comment if operational and/or safety challenges
inuenced research activities during the pandemic.
Future studies are needed probing the number of
research projects that were halted or suspended
earlier than the intendend time-point of evaluation
or if there were changes in data collection methods
and measured outcomes. Moreover, global data
is still needed to compare current national status
with different countries and trended research
topics as well as quality of conducted research
during and post-pandemic period.
CONCLUSION
There was a decrease in the number of
publications during the pandemic in Turkey
limited to two years period following declaration
of pandemic. The present study highlighted the
impact of the COVID-19 pandemic on publication
rate in periodontology and implantology elds in
Turkey. As the COVID-19 pandemic is not over,
institutions and governments should prepare
a guideline for researchers and policy makers
that will guide researchers to correctly/timely
decide to continue or suspend clinical trials while
ensuring scientic progress safely and efciently.
Author’s Contributions
AA: Conceptualization, Methodology, Writing
– Original Draft Preparation, Writing – Review
& Editing, Supervision. MSY: Methodology,
Validation, Investigation, Data Curation, Review
& Editing. MEA: Data preperation, Statistical
Analysis, Resources. HE: Conceptualization,
Methodology, Review & Editing, Supervision.
Figure 5 - Keywords and frequencies of studies published during the pandemic.
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Impact of the COVID-19 pandemic on publication rate in periodontology and implantology in T urkey
Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
Conict of Interest
The authors have no proprietary, nancial,
or other personal interest of any nature or kind
in any product, service, and/or company that is
presented in this article.
Funding
This research did not receive any specic
grant from funding agencies in the public,
commercial, or not-for-prot sectors.
Regulatory Statement
This research did not involve any human
and-or animal participants, therefore no ethical
approval is needed.
REFERENCES
1. World Health Organization. Rational use of personal protective
equipment for COVID-19 and considerations during severe
shortages: interim guidance [Internet]. Switzerland: WHO;
2020 [cited 2022 Oct 18]. Available from: WHO/2019-nCoV/
IPC_PPE_use/2020.4.
2. Kılıçarslan MA, Şenel FÇ, Özcan M. Assessment of dental care
during the COVID-19 pandemic in Turkey and future projections.
Braz Dent Sci. 2020;23(2):1-7. https://doi.org/10.14295/
bds.2020.v23i2.2260.
3. Schwendicke F, Krois J, Gomez J. Impact of SARS-CoV2
(Covid-19) on dental practices: economic analysis. J Dent.
2020;99:103387. http://dx.doi.org/10.1016/j.jdent.2020.103387.
PMid:32473182.
4. Nibali L, Ide M, Ng D, Buontempo Z, Clayton Y, Asimakopoulou K.
The perceived impact of Covid-19 on periodontal practice in the
United Kingdom: a questionnaire study. J Dent. 2020;102:103481.
http://dx.doi.org/10.1016/j.jdent.2020.103481. PMid:32979456.
5. Menhadji P, Patel R, Asimakopoulou K, Quinn B, Khoshkhounejad
G, Pasha P, etal. Patients’ and dentists’ perceptions of tele-
dentistry at the time of COVID-19. A questionnaire-based
study. J Dent. 2021;113:103782. http://dx.doi.org/10.1016/j.
jdent.2021.103782. PMid:34400252.
6. Harper L, Kalfa N, Beckers GMA, Kaefer M, Nieuwhof-Leppink
AJ, Fossum M,etal. The impact of COVID-19 on research. J
Pediatr Urol. 2020;16(5):715-6. http://dx.doi.org/10.1016/j.
jpurol.2020.07.002. PMid:32713792.
7. Ali JK, Riches JC. The impact of the Covid-19 pandemic on oncology
care and clinical trials. Cancers (Basel). 2021;13(23):5924. http://
dx.doi.org/10.3390/cancers13235924. PMid:34885038.
8. Boughey JC, Snyder RA, Kantor O, Zheng L, Chawla A, Nguyen
TT,etal. Impact of the COVID-19 pandemic on cancer clinical
trials. Ann Surg Oncol. 2021;28(12):7311-6. http://dx.doi.
org/10.1245/s10434-021-10406-2. PMid:34236550.
9. Sohrabi C, Mathew G, Franchi T, Kerwan A, Griffin M, Soleil C Del
Mundo J,etal. Impact of the coronavirus (COVID-19) pandemic
on scientific research and implications for clinical academic
training - A review. Int J Surg. 2021;86:57-63. http://dx.doi.
org/10.1016/j.ijsu.2020.12.008. PMid:33444873.
10. van Eck NJ, Waltman L. Software survey: VOSviewer, a computer
program for bibliometric mapping. Scientometrics. 2010;84(2):523-
38. http://dx.doi.org/10.1007/s11192-009-0146-3. PMid:20585380.
11. Rocha-Gomes G, Flecha OD, Miranda TS, Duarte PM, Shaddox
LM, Galvão EL,etal. Impact of the coronavirus disease 2019
pandemic on periodontal practice: a questionnaire survey. J
Clin Periodontol. 2021;48(4):541-9. http://dx.doi.org/10.1111/
jcpe.13427. PMid:33474762.
12. Akacha M, Branson J, Bretz F, Dharan B, Gallo P, Gathmann I,etal.
Challenges in assessing the impact of the covid-19 pandemic on
the integrity and interpretability of clinical trials. Stat Biopharm
Res. 2020;12(4):419-26. http://dx.doi.org/10.1080/19466315.2
020.1788984. PMid:34191974.
13. Schonhaut L, Costa-Roldan I, Oppenheimer I, Pizarro V, Han
D, Díaz F. Scientific publication speed and retractions of
COVID-19 pandemic original articles. Rev Panam Salud Publica.
2022:46:e25. http://dx.doi.org/10.26633/RPSP.2022.25.
14. Jacimovic J, Jakovljevic A, Nagendrababu V, Duncan HF, Dummer
PMH. A bibliometric analysis of the dental scientific literature on
COVID-19. Clin Oral Investig. 2021;25(11):6171-83. http://dx.doi.
org/10.1007/s00784-021-03916-6. PMid:33822288.
Mehmet Selim Yildiz
(Corresponding address)
Altinbas University, Faculty of Dentistry, Department of Periodontology, Istanbul,
Turkey.
Email: mehmet.yildiz2@altinbas.edu.tr
Date submitted: 2022 Oct 18
Accept submission: 2022 Nov 28
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Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in periodontology and implantology in T urkey
Akcalı A et al.
Impact of the COVID-19 pandemic on publication rate in
periodontology and implantology in Turkey
Supplementary les
Supplementary material accompanies this paper.
Table S1 - Search strategy for Web of Science, MEDLINE, Cochrane Library and SCOPUS
This material is available as part of the online article from https://doi.org/10.4322/bds.2023.e3667
