1 Volume 23 2024 e245039 Critical Review Braz J Oral Sci. 2024;23:e245039http://dx.doi.org/10.20396/bjos.v23i00.8675039 1 Health Sciences Graduate Program, Federal University of Sergipe, Aracaju, Sergipe, Brazil. 2 Department of Dentistry, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil. Corresponding author: Aurélio de Oliveira Rocha Postgraduate Program of Dentistry / Federal University of Santa Catarina. Campus Universitário - Bloco H - Trindade Florianopolis, Santa Catarina, 88040-900, Brazil Phone: +55 79 99894-6359 E-mail: aureliorocha2015@gmail.com Editor: Dr. Altair A. Del Bel Cury Received: November 18, 2023 Accepted: February 04, 2024 A bibliometric analysis of the top 100 most-cited articles concerning the use of propolis in dentistry Johnny Alexandre Oliveira Tavares1 , Aurélio de Oliveira Rocha2,* , Lucas Menezes dos Anjos2 , Mariane Cardoso2 , Francilene Amaral da Silva1 Aim: The objective of this bibliometric analysis was to identify and analyze the key characteristics of the 100 most-cited articles related to the use of propolis in dentistry. Methods: The search was conducted in the Web of Science Core Collection, and two independent reviewers selected the articles, excluding meeting articles. The number of citations for each article was compared across the Scopus and Google Scholar databases. The extracted data included the number and density of citations, year of publication, journal and impact factor, study design and theme, country and continent, institution, keywords, and authors. VOSviewer software was employed to generate collaborative network maps. Spearman correlation and Poisson regression analyses were performed on the data. Results: The number of citations ranged from 26 to 247, with a citation density varying between 1.08 and 20.00. Articles were published between 1991 and 2021, with laboratory studies (70%) and antimicrobial activity (39%) being the most prevalent study design and theme, respectively. The most discussed dental specialty was microbiology (49%). Rosalen PL (27%) emerged as the author with the highest number of articles, and the University of Campinas (Brazil) was the most prolific institution. Poisson regression indicated a declining trend in citations over the years, though literature reviews exhibited higher citation performance. Brazil contributed the highest percentage of articles (41%). Conclusion: In conclusion, the 100 most-cited articles predominantly comprised laboratory studies investigating the antimicrobial activity of propolis, primarily originating from Brazil, with notable emphasis on the University of Campinas. Keywords: Propolis. Biological products. Dentistry. Oral health. Bibliometrics. https://orcid.org/0000-0002-5492-4407 https://orcid.org/0000-0002-9308-2118 https://orcid.org/0000-0001-5100-0789 https://orcid.org/0000-0001-9936-7942 https://orcid.org/0000-0001-6729-2843 2 Tavares et al. Braz J Oral Sci. 2024;23:e245039 Introduction Natural origin products are extensively studied due to their therapeutic potential for various diseases, with a lower risk of adverse effects1. Currently, 80% of the world’s population uses natural products or phytotherapeutics2. Thus, there has been an exponential increase in the evaluation and utilization of bee products such as propolis in various healthcare areas due to the efficacy of its pharmacological properties3. Propolis is a mixture of resin collected by bees, dependent on the availability of regional plants, geographical conditions, local climate, and the age of the bees4. It has a diverse composition of resins, sap flowers, wax, trees, pollen, aromatic oils, and essential oils5. Bees use it to seal spaces, increase hive temperature, and pro- tect against the entry of microorganisms6. Chemically, its composition presents an immense diversity of molecular compounds such as vitamins, amino acids, miner- als, polyphenols, flavonoids, terpenoids, and phenolic acids, consequently exhibiting broad biological activity7. Among the main biological properties of propolis described in the literature, notable actions include antibacterial, anti-acne, hepatoprotective, anticancer, anti-inflamma- tory, anti-SARS-CoV-2, antifungal, antioxidant, and neuroprotective effects8,9. Its use in dentistry has shown promising results, especially for the control of periodontal diseases such as periodontitis and gingivitis, storage and transportation of avulsed teeth, dentin hypersensitivity, oral mucositis, prosthetic stomatitis, endodontic irrig- ant, cold sores, and aphthous ulcers3,10. Bibliometric analysis employs quantitative tools based on data extracted from pub- lished studies to reveal scientific trends in a specific clinical field. In broad areas with a high number of publications, it is suggested to analyze the most relevant articles in terms of citation count11. Therefore, by analyzing the citations of an article, it quanti- tatively demonstrates the importance of that area, providing insights into future per- spectives on a specific topic based on classical articles, as well as recognizing institu- tions, authors, countries, and journals12. In this context, some previous studies conducted bibliometric analyses on relevant dental topics to determine the scientific status of a particular subject11,13. However, to our knowledge, no bibliometric review has been conducted on the use of propolis in dentistry, making this the first. Therefore, this study aims to analyze the key charac- teristics of the 100 most-cited articles related to the use of propolis in dentistry, iden- tifying authors, journals, countries, institutions, study designs, and prominent themes. Methodology Information Sources and Search Strategy On June 8, 2023, an electronic search was conducted in the Web of Science Core Collection (WoS-CC) database. The following search strategy was employed for study selection: TS = (“Propolis” OR “Green Propolis” OR “Red Propolis” OR “Honeybee” OR 3 Tavares et al. Braz J Oral Sci. 2024;23:e245039 “Polish Propolis”) AND (Dentistry OR “Diagnosis, Oral” OR “Oral Diagnosis” OR “Oral Medicine” OR “Dental Science” OR “Oral Research” OR “Oral Health”). Eligibility Criteria Studies included in this bibliometric analysis investigated, described, or mentioned the properties of propolis in dental applications. There were no restrictions on the year of publication or language. Excluded publications were those where propolis was not used for dental purposes, as well as conference articles, editorials, and meeting abstracts. Selection Process Identified articles were arranged in descending order based on the absolute num- ber of citations. Three independent reviewers (JAOT, AOR, and LMA) selected arti- cles after reviewing the title, abstract, and full text when necessary. Discrepancies were resolved through consensus with a fourth reviewer (FAS). In case of a tie in the number of citations, the article’s position on the list was based on the higher density (number of citations per year) from WoS-CC. Data Extraction Bibliometric data were extracted for each article, including the number of citations, publication year, journal, impact factor (IF) (Journal Citation Reports from Clarivate Analytics, 2021), study design, theme, country and continent, institution (based on the corresponding author’s affiliation), keywords, and authors. Study designs were classified as systematic reviews, literature reviews, laboratory studies, and interven- tion studies. Two researchers (AOR and LMA) extracted the data. Subsequently, the number of citations for each selected article was cross-referenced with Scopus and Google Scholar. Articles were grouped into two themes. The first theme addressed the primary objec- tives related to the use of propolis in the study, categorized into: anti-inflammatory, antimicrobial activity, anti-plaque, aphthous ulcers, chronic periodontitis, dental caries, oral cancer, pulp protection, and re-implanted teeth. The second theme grouped stud- ies based on the associated dental specialty: endodontics, microbiology, periodontics, oral pathology, and traumatology. Studies appearing only once and not fitting into the mentioned themes were classified as “others.” Extracted data were transferred to Mic- rosoft Excel® 2010 for categorization. Statistical Analysis The Visualization of Similarities Viewer (VOSviewer, Leiden University, Netherlands) software was used to generate a graphical representation of bibliometric networks, illustrating the connections between authors and keywords. Circle size is propor- tional to the data strength in the network. Items represented by similar colors and interconnected in the same cluster demonstrate correlation between the data. The Kolmogorov-Smirnov test assessed data distribution normality. Spearman’s correla- tion coefficient test, due to non-normal distribution, was used for statistical analysis. Poisson regression analysis determined associations between the number of cita- 4 Tavares et al. Braz J Oral Sci. 2024;23:e245039 tions (WoS-CC) and the journal’s impact factor, study design, continent, and year of publication. These analyses were conducted using IBM SPSS Statistics for Windows version 24.0 (IBM Corp.) with a significance level of 5% (p = 0.05). Results Search Results The primary search yielded 698 articles, which were organized in descending order based on the number of citations. To identify the top 100 most-cited articles related to the use of propolis in dentistry, the first 160 documents were analyzed, of which 60 were excluded for not addressing the proposed theme. After the selection process, the top 100 most-cited articles related to the use of propolis in dentistry were identi- fied (Supplementary Table 1). Citation Analysis The top 100 articles received a total of 6,553 citations in WoS-CC. The number of citations ranged from 26 to 247. Self-citations accounted for 6.7% (n=436) of WoS-CC citations. Fifteen articles were cited more than 100 times. In the other two databases, a higher number of citations was observed, with 7,767 (ranging from 28 to 293) in Scopus and 15,205 (ranging from 22 to 556) in Google Scholar. There was a strong positive correlation between the number of citations in WoS-CC and Google Scholar (rho = 0.820; p <0,001) and a very strong positive correlation between WoS-CC and Scopus (rho = 0.953; p <0,001). The findings reveal a consistent trend in the number of citations across databases, particularly between WoS-CC and Scopus. The most-cited article in WoS-CC14, accumulating an average of 15.44 citations per year, was also the most-cited in Google Scholar (556 citations). However, another study performed better in Scopus15. The second most-cited article in WoS-CC16, accu- mulating an average of 11.62 citations per year, was also the second most-cited in Scopus (288 citations). However, the second most-cited in Google Scholar (554 cita- tions) was the first most-cited in Scopus15. The article with the highest citation density in WoS-CC (20.00)17 was a literature review published in the journal Foods. The second article with the highest citation density in WoS-CC (17.17)18 was a literature review published in the Archives of Oral Biology. Year of Publication The oldest article was published in 199119, and the most recent articles were pub- lished in 202117,20. The majority of articles among the top 100 cited (n=58) were pub- lished in the decade between 2007 and 2016. A description of the number of publi- cations each year can be seen in Supplementary Figure 1. The Poisson regression analysis indicated a correlation between the number of citations in WoS-CC and the publication year of the studies. Specifically, the number of WoS-CC citations exhibited a decrease of 4.5% per year (RR: 0.955; 95% CI: 0.951-0.959; p < 0.001) (Table 1). This outcome suggests that, on average, older articles tended to accumulate a higher number of citations. 5 Tavares et al. Braz J Oral Sci. 2024;23:e245039 Fig 1. Worldwide distribution of the origin of publications on propolis and dentistry. The continents then delimited in lighter tones and the countries associated with the articles are identified with darker tones referring to their continent. Brazil and South America stand out with the highest number of publications. Table 1. Poisson regression between the total number of WOS-CC citations and independent variables Independent variables WOS-CC number of citations RR (95% CI) p Study design Laboratorial 1 Literature review 1.453 (1.349 – 1.566) <0.001 Interventional 0.796 (0.733 – 0.865) <0.001 Systematic review 1.044 (0.763 – 1.429) 0.786 Continent South America 1 North America 1.040 (0.970 – 1.115) 0.269 Asia 0.893 (0.840 – 0.950) <0.001 Europe 0.692 (0.632 – 0.757) <.001 Africa 0.942 (0.808 – 1.099) 0.447 Oceania 0.685 (0.497 – 0.944) 0.012 Year of publication 0.955 (0.951 – 0.959) <0.001 Journals’ impact factor 1.021 (1.015 – 1.028) <0.001 Legend: (CI) confidence interval, (RR) rate ratio, (WOS-CC) Web of Science Core Collection Contributing Journals and Impact Factor The journals in which the top 100 articles were published are presented in Supple- mentary Table 2. Evidence-Based Complementary and Alternative Medicine was the 6 Tavares et al. Braz J Oral Sci. 2024;23:e245039 top journal, with eight articles (285 citations), followed by Archives of Oral Biology (494 citations), Caries Research (468 citations), and Journal of Endodontics, each with five articles. According to journal citation reports, the journals with the high- est impact factors (IF) in 2021 related to propolis use in dentistry were: Interna- tional Journal of Oral Science with two articles (IF 24.897; 84 citations), Journal of Advanced Research with one article (IF 12.822; 48 citations), and Current Opinion in Biotechnology with one article (IF 10.279; 45 citations). The Poisson regression analysis revealed that for a unit increase in impact factor, the number of WoS-CC citations tended to increase by 2.1% (RR: 1.021; 95% CI: 1.015-1.028; p < 0.001) (Table 1). This finding suggests that, on the whole, articles published in journals with higher impact factors exhibited a greater likelihood of garnering a higher number of citations. Table 2. Top 10 institutions with the highest number of articles among the 100 most-cited. Institution Country Number of articles Number of citations University of Campinas Brazil 17 1,398 University of Sao Paulo Brazil 7 695 Medical University of Silesia Poland 6 254 University of Rochester USA 5 672 Federal University of Minas Gerais Brazil 5 238 Shahid Beheshti University of Medical Science Iran 3 88 Ege University Turkiye 2 289 Cumhuriyet University Turkiye 2 121 University of Florida USA 2 99 University of Pittsburgh USA 2 89 Study Design and Themes The majority of studies were laboratory-based (n=70; 4,721 citations), followed by lit- erature reviews (n=15; 1,071 citations), intervention studies (n=14; 720 citations), and one systematic review (n=1; 41 citations). The Poisson regression analysis indicated that the number of citations was influenced by the study design (p < 0.001), as shown in Table 1. In general, literature reviews exhibited superior citation performance com- pared to laboratory studies. This finding suggests that despite a smaller number of publications, literature reviews had a higher likelihood of being cited compared to other study designs. Concerning the primary theme, the following distribution was observed: antimicro- bial activity (n=39; 2,933 citations), dental caries (n=22; 1,686 citations), others (n=9; 352 citations), replanted teeth (n=7; 312 citations), antiplaque (n=6; 362 citations), oral cancer (n=5; 369 citations), pulp protection (n=4; 175 citations), anti-inflamma- tory (n=4; 154 citations), chronic periodontitis (n=2; 107 citations), and aphthous ulcer (n=2; 103 citations). For the secondary theme, the following distribution was 7 Tavares et al. Braz J Oral Sci. 2024;23:e245039 observed: microbiology (n=49; 4,013 citations), oral pathology (n=21; 1,163 citations), periodontics (n=11; 540 citations), endodontics (n=11; 499 citations), traumatology (n=7; 312 citations), and others (n=1; 26 citations). Countries and Continents A total of 21 countries contributed to the top 100 most-cited articles. Consider- ing the number of publications per country, the top three were Brazil (n=41; 2,835 citations), the United States of America (n=13; 1,133 citations), and Turkey (n=10; 723 citations). Among continents with more articles in the top 100 (Figure 1), South America (n=41; 2,835 citations) and Asia (n=26; 1,643 citations) stood out. The Pois- son regression analysis revealed an association between the continents of Europe (p < 0.001), Asia (p < 0.001), and Oceania (p = 0.012) with the number of WoS-CC citations, as shown in Table 1. However, these continents demonstrated lower cita- tion trends compared to South America. This outcome suggests that, irrespective of the number of publications, articles originating from South America have a greater tendency to be cited. Institutions A total of 55 institutions contributed to the top 100 most-cited articles. Table 2 pres- ents the top 10 institutions with the highest number of publications. Ties were resolved considering the highest number of citations. The top three positions belonged to the University of Campinas (Brazil) with 17 articles and 1,398 citations, the University of São Paulo (Brazil) with 7 articles and 695 citations, and the Medical University of Sile- sia (Poland) with 6 articles and 254 citations. Keywords A total of 563 keywords were identified in the top 100 most-cited articles. The most prevalent term was propolis (n=56), followed by antibacterial activity (n=26), chemical composition (n=24), antimicrobial activity (n=24), and Brazilian propolis (n=22). Figure 2 displays the most prevalent keywords (5 or more occurrences) and their relationships. Keywords that correspond to larger foci and appear in bold are the terms that had higher occurrences. On the other hand, keywords appearing in smaller foci had lower occurrences. Keywords connected in bibliometric networks are terms that showed a relationship between studies. 8 Tavares et al. Braz J Oral Sci. 2024;23:e245039 Fig 2. Frequency and interaction of the main keywords associated with the study. The terms associated with the biggest points and highlighted writings are more prominent. Terms linked by lines and associated with points with the same color indicate greater contribution. Authors A total of 406 authors contributed to the top 100 most-cited articles. Table 3 shows the top 10 authors with the highest number of publications. Prominent authors included Rosalen PL (n=27; 2,592 citations), Ikegaki M (n=18; 1,536 citations), Koo H (n=16; 1,617 citations), Alencar SM (n=16; 1,209 citations), and Cury JA (n=13; 1,584 citations). The frequency of their appearances and co-authorship relationships are represented in Figure 3 (three or more occurrences). Names written in bold and cor- responding to the red/orange color are associated with the most frequent authors. Conversely, names associated with the green/blue color correspond to authors with lower occurrences. Table 3. Top 10 authors with more publications among the 100 most-cited articles. Authors Number of articles among 100 most-cited Number of citations among the 100 most-cited articles Number of articles published in WoS-CC Number of citations in WoS-CC H-Index Rosalen PL 27 2,592 251 7,467 50 Ikegaki M 18 1,536 58 2,718 29 Koo H 16 1,617 21 418 4 Continue 9 Tavares et al. Braz J Oral Sci. 2024;23:e245039 Continuation Alencar SM 16 1,209 207 5,759 42 Cury JA 13 1,584 391 8,020 49 Park YK 9 1,103 21 2,122 15 Bowen WH 6 662 418 8,691 48 Bueno-Silva B 5 364 44 1,235 20 Dziedzic A 5 225 61 1,138 19 Duarte S 4 307 54 1,461 20 Fig 3. Main groups/authors who conducted researched on propolis and dentistry. The authors present in the same cluster indicate groups and collaboration between authors. The names associated with red-colored foci indicate greater contributions from the authors. Discussion The apicultural products are widely used in traditional and alternative dentistry due to their effective results against inflammatory and infectious processes, thus character- izing a promising area. Consequently, numerous studies have been conducted evalu- ating and investigating the properties of propolis in dentistry21. In this perspective, the present study analyzed the main characteristics of the 100 most-cited articles on the use of propolis in dentistry in the WoS-CC database. There was a greater tendency in laboratory research investigating the use of propolis for antimicrobial purposes, mainly originating from Brazil. 10 Tavares et al. Braz J Oral Sci. 2024;23:e245039 The utilization of citation indicators serves as a tool for evaluating the scientific per- formance of research groups, topics, and institutions22. Consequently, the current study reveals a substantial number of citations among the 100 most-cited articles on the use of propolis in dentistry, in comparison to other bibliometric studies12,23. In a specific study area, a classic article is typically anticipated to accumulate at least 100 citations24. It is worth noting that 15% of the articles analyzed in WoS-CC in this review exceeded this metric. Self-citations were incorporated into the over- all count of the most-cited articles. Analyzing self-citations, a considerable number was observed. Although self-citation is not viewed positively, it may occur because authors belonging to the same research group conduct various experiments on a specific topic25. In these instances, self-citations are not viewed as a negative practice; instead, they are recognized as a result of authors making substantial contributions to a specific area of knowledge. Moreover, in previous studies, it has been observed that self-citations did not significantly impact the ranking order of a most-cited list12,13. The most-cited article in WoS-CC aimed to evaluate the antimicrobial, antioxidant, and cytotoxic activity and analyze the chemical composition of red propolis, present- ing promising results and new biologically active compounds. This may have encour- aged further studies based on laboratory results. It is noteworthy that red propolis has gained increasing relevance in the international market, originating from tropical countries, with flavonoids as its main compounds14. Google Scholar encompasses a larger number of indexed journals and incorporates citations from books and thesis documents, leading to a notable disparity in the count of citations when compared to WoS-CC12. Nevertheless, Spearman’s correlation analysis demonstrated a robust correlation between the number of citations in these databases, aligning with findings in other bibliometric reviews11,13. A crucial point during citation analysis is that the absolute number of citations may differ from its density, as older articles generally have a higher probability of being cited more times in absolute terms26. In this study, it is evident that the most-cited article in absolute numbers does not have the highest number of citations per year, as another article led the citation density in WoS-CC17. This can be explained because narrative reviews cover a broader range of topics compared to laboratory studies27. Nonetheless, the Poisson regression analysis indicated that older articles exhibited a significant tendency to accumulate higher citation counts. Although the first article on the topic was published in 1991, the highest concentra- tion of publications among the top 100 most-cited works occurred between 2007 and 2016, indicating that it is a current and relevant topic with the development of many studies yielding promising results. Despite the abundance of studies on prop- olis, there are still many gaps in the literature regarding biological activities such as antimicrobial, antifungal, and antiviral effects, as well as synergies with other products due to the various types produced in apiculture centers such as New Zealand, Brazil, and Australia28. Thus, propolis-based products have been developed by dental indus- tries, supported by laboratory and clinical studies for various pathologies, including gingivitis, aphthous ulcers, oral candidiasis, and herpes, among others29. 11 Tavares et al. Braz J Oral Sci. 2024;23:e245039 One of the most relevant actions of propolis is its broad antimicrobial capacity, attributed to the presence of flavonoids and phenolic compounds, which may be linked to a direct action on microorganisms or the activation of the immune system. This mechanism interferes with the rupture of the cell membrane, membrane perme- ability, and adenosine triphosphate production30. Considering the effect of this sub- stance on the cellular organism, it is crucial to conduct multiple laboratory studies to confirm its safety for use in humans. This fact justifies the emphasis on laboratory studies as the most frequent study design in the top 100. Supporting the antimicrobial activity of propolis, this theme gained prominence among studies primarily related to microbiology. However, the Poisson regression analysis result indicated that literature reviews demonstrated superior performance in terms of the number of citations. This could be attributed to the emphasis on citations even with a smaller number of litera- ture review articles. There was a considerably low number of intervention articles and systematic reviews. Therefore, the present analysis highlights the need to increase the number of randomized clinical trials and consequently systematic reviews to enhance the level of scientific evidence on the efficacy of propolis in dental pathologies. It is known that randomized clinical trials are considered the “gold standard” to serve as a reference for clinical decision-making in each therapy31. However, their execu- tion requires establishing several factors that depend on the availability of patients, materials, and specific pathologies32. This fact may explain the low number of arti- cles with such a study design. Considering the scientific journals in which the most-cited articles were published, most had a broad scope, possibly reflecting the use of propolis in various health areas4. Among the top 10 journals, only three were exclusively related to dentistry. Regarding the impact factor, it is noteworthy that the Journal Citation Reports con- siders only journals indexed in WoS-CC25. The Poisson regression analysis indicated a subtle trend of publications towards higher journal impact factors. In terms of contributing countries, Brazil had the highest number of publications in the current top 100. The United States of America ranked second, as shown in a previous bibliometric review on apitherapy in complementary medicine33. An asso- ciation can be made because Brazil is one of the world’s largest propolis produc- ers, thus leading research in this field. Another important factor is the significant variation in the types of propolis produced in Brazil34. Additionally, South America stood out as the continent with the highest number of publications, with Brazil being the only South American country that produced studies on this theme. According to the Poisson regression analysis, this continent exhibited higher citation trends compared to others, potentially associated with the large number of documents originating from this continent. Asia ranked second, despite being separate from the second most prominent country. The combination of other Asian countries provided visibility to the Asian continent. Brazil’s prominence as the most frequent country reflected in the most prolific institutions, where the top two were Brazilian institutions: the University of Campinas ranked first, and the University of São Paulo ranked second. 12 Tavares et al. Braz J Oral Sci. 2024;23:e245039 The authors who stood out in the most-cited articles were Rosalen PL, Ikegaki, Koo H, Alencar SM, and Cury JA. The collaboration network performed in Vosviewer demonstrated that these authors belonged to the same cluster, indicating their par- ticipation in a common research group, all affiliated with Brazilian institutions. Addi- tionally, it was observed that this group primarily focused on conducting laboratory studies analyzing the antimicrobial activity of propolis in dentistry, with applications mainly in microbiology. A strength observed in this study is the absence of filters limiting the year of publica- tion, citations, or language, allowing for a comprehensive and complete analysis of all documents published on the topic up to the search date. However, the broad time window may compromise the assessment of authors who are no longer actively engaged in research, yet it ensures a fair retrieval of the most-cited articles without excluding older and relevant contributions on the topic. The inclusion of authors irrespective of their position in the article may introduce bias to this review. Never- theless, focusing solely on first-position authors could potentially exclude important researchers who contributed significantly to the development of this topic. Another limitation of this study is the reliance solely on the WoS-CC database, without con- sidering other available bibliometric databases such as Scopus, Medline, and Goo- gle Scholar. The decision to use only WoS-CC was based on its prominence in sig- nificant bibliometric analyses in dentistry, being considered the most prestigious database for such analyses and providing a suitable interface for document selec- tion and export in various formats11-13. This bibliometric analysis covers the 100 most-cited articles related to the use of propolis in dentistry. The majority of these articles were published in Brazil, the USA, and Turkey, with a notable emphasis on laboratory studies, particularly addressing the topic of antimicrobial activity. The findings highlight a need to elevate the level of sci- entific evidence by promoting well-designed randomized clinical trials, subsequently enabling the conduct of systematic reviews with meta-analysis. Acknowledgment This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nivel Superior – Brazil (CAPES), grant number 001. Conflicts of interest None. 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