Reporting characteristics of systematic review abstracts published in the proceedings of the SBPqO meeting

s allow 1,470 characters, 120 in the title and 1,350 in the body of the text19. Also, the recommendations of the International Association for Dental Research20 General Session for abstracts allow 300 words or less, which is better than SBPqO, but it is still limited. We believe that it would be better to expand the number of words accepted in abstracts, but there are costs involved in this process. Also, one crucial aspect is including the use of reporting guidelines in the instructions to authors to help in the abstract writing. The most important limitation of our study is that we did not assess the abstracts published before the establishment of a systematic review section, and it is impossible to evaluate the impact of this establishment in terms of the number of systematic reviews abstracts and reporting quality, and we did not assess all items recommended by PRISMA for abstracts. We believe that future assessments should focus on spin strategies and the extent and level of spin involved in systematic reviews abstracts. Thus, in light of the existence of a specific guideline for systematic review abstracts (PRISMA 2020)17, the SBPqO, which is the most important conference in oral health research in Brazil, should endorse the use of this statement to improve the reporting of abstracts and encourage students and researchers to use it. In conclusion, based on this study, the reporting characteristics of systematic review abstracts published in the proceedings of the SBPqO meeting are satisfactory. However, there is room for improvement. Acknowledgements This study was conducted in a Graduate Program supported by CAPES, Brazil (Finance Code 001). RSO is funded in part by Meridional Foundation (Passo Fundo, Brazil), and WVOS is funded by the National Council for Scientific and Technological Development (CNPq, Brazil). However, these supporters had no role in the design of the study, in the collection or analysis of data, in the decision to publish or in preparing the manuscript. Data availability Datasets related to this article will be available upon request to the corresponding author.


Introduction
A systematic review is an important tool in health, and it is used for identifying, appraising, and integrating the results of a specific field 1,2 . The number of systematic reviews in dentistry has been increasing in recent years, and the reporting quality is highly variable [3][4][5] .
Much health research is presented at conferences and is publicly available as abstracts in the proceedings. The reporting quality of these abstracts is important because systematic reviewers will in some situations decide to include a study (or not) based on the conference abstract because the full article is not available. The reporting quality of conference abstracts was assessed in different topics in health, including sports injury prevention, oncology, urology, psychiatry, surgery, and oral health 6-13 . However, there are no studies assessing abstracts of systematic reviews in dentistry published in the proceedings of conferences.
The Sociedade Brasileira de Pesquisa Odontológica (SBPqO) meeting is the most important conference in oral health research in Brazil, and it is the Brazilian division of the International Association for Dental Research. Since 2019, the SBPqO meeting has presented a special section dedicated to systematic review presentation, and all studies are published in the proceedings of the SBPqO meeting 14,15 . Therefore, this study aimed to assess the reporting characteristics of systematic review abstracts published in the proceedings of the SBPqO meeting.

Eligibility criteria and search
We included abstracts mentioning that a systematic review was conducted in the title, objective, or methods sections, regardless of the dental specialization discussed. We excluded studies which cited performing scoping reviews, overviews or assessing reporting quality of studies, or other methodological aspects characterizing the study as a meta-research.
We performed a search in the proceedings of 2019 14 and 2020 15 to identify abstracts based on the eligibility criteria cited above, examining only the Systematic Reviews section.

Screening
Two researchers initially performed a pilot screening test discussing the inclusion criteria using the 2018 proceedings of the SBPqO meeting. One of the researchers subsequently identified studies by reviewing the titles and abstracts through the pdf versions of the 2019 and 2020 proceedings available at www.sbpqo.org.br. In case of any doubts, the opinion of a second researcher was requested.

Data extraction
We created a standardized form using the Excel program (Microsoft Excel 2020). We initially performed a pilot data extraction through a discussion between two reviewers to consider all data for extraction. Data from each systematic review were subsequently extracted by one reviewer. The following data were collected: affiliation of primary author, dental specialization (Public Health, Endodontics, Oral and Maxillofacial Pathology/stomatology, Radiology, Oral and Maxillofacial Surgery, Restorative and Esthetic Dentistry, Pediatric Dentistry, Periodontics, Orthodontics/Orthopedics, Implantology, and Others), the term "systematic review" mentioned in the title (Yes or No), reporting of the objective (Yes or No), reporting of eligibility criteria (Only inclusion criteria, Only exclusion criteria, Inclusion and exclusion criteria, Unclear, Not reported), reporting of information sources (Only databases, Only date of search, Databases and date of search, Unclear, Not reported), reporting of the number of included studies (Yes, No, Unclear) and if a meta-analysis was performed (Yes or No).

Data analysis
A descriptive analysis of the data was performed with the data summarized as frequencies using the Excel program (Microsoft Excel 2020).

Results
We identified 262 abstracts published in the proceedings of the SBPqO meeting and classified as "systematic review". We included 235 abstracts after the screening based on the eligibility criteria (see Supplemental Material). Table 1 presents the data related to the affiliation of the primary author and the dental specialization of the abstract. As a result, 20 studies were from the Universidade de Uberlândia (8.5%), followed by the Universidade de Santa Catarina (n=16;6.8%), while the Universidade Federal do Pará, Universidade Federal do Rio de Janeiro, Faculdade de Odontologia de Piracicaba (UNICAMP), and the Universidade Estadual Paulista (Araçatuba) presented 15 studies each (6.4%). The main specialization was Restorative and Esthetic Dentistry, numbering 47 studies (20%), followed by Oral and Maxillofacial Pathology/stomatology (n=41; 17.4%).  Figure 1 presents the reporting characteristics of the included abstracts. Most of studies mentioned the term "systematic review" in the title (n=219; 93.2%) and reported the objective (n=231; 98.3%). A great majority of studies did not report the eligibility criteria (n=97; 41.3%) or it was classified as unclear (n=96; 40.8%). In addi-

Discussion
This is the first study in dentistry to assess the reporting characteristics of systematic review abstracts published in proceedings of conferences. Our results demonstrated that most of the aspects evaluated are well-reported, and we believe that results could be related to the fact that the conference abstracts included were peer-reviewed by experienced reviewers before the publication of conference proceedings. Also, our results are significant because the abstract could become a pivotal element to support clinical decision-making in some situations, as highlighted by Johnson et al. (2013) 16 .
However, most studies did not report the eligibility criteria, or it was classified as unclear. This fact could be related to the limited number of words to write the abstract. Details about what evidence was eligible or ineligible are important to the readers to comprehend the review scope. One of the possibilities to report the eligibility criteria is to use the PICO framework highlighting the Population, Intervention, Comparator, and Outcome included in the review 17 .  18 showed that systematic reviews are well accepted as a Master's or PhD thesis by Brazilian graduate programs in dentistry; and 3) Brazil has an upper-middle-income economy and systematic reviews are cheaper than other methodologies such as randomized controlled trials resulting in a research methodology appropriate for this setting 18 .
When analyzing the primary authors' affiliation, we can observe universities from different regions of Brazil which presented systematic reviews in the SBPqO meeting. The top university contributors could be the institutions where systematic reviews are well accepted in graduate programs, reflecting in their students presenting systematic reviews in that meeting.  19 . Also, the recommendations of the International Association for Dental Research 20 General Session for abstracts allow 300 words or less, which is better than SBPqO, but it is still limited. We believe that it would be better to expand the number of words accepted in abstracts, but there are costs involved in this process. Also, one crucial aspect is including the use of reporting guidelines in the instructions to authors to help in the abstract writing.
The most important limitation of our study is that we did not assess the abstracts published before the establishment of a systematic review section, and it is impossible to evaluate the impact of this establishment in terms of the number of systematic reviews abstracts and reporting quality, and we did not assess all items recommended by PRISMA for abstracts. We believe that future assessments should focus on spin strategies and the extent and level of spin involved in systematic reviews abstracts.
Thus, in light of the existence of a specific guideline for systematic review abstracts (PRISMA 2020) 17 , the SBPqO, which is the most important conference in oral health research in Brazil, should endorse the use of this statement to improve the reporting of abstracts and encourage students and researchers to use it.
In conclusion, based on this study, the reporting characteristics of systematic review abstracts published in the proceedings of the SBPqO meeting are satisfactory. However, there is room for improvement.