Studies reporting original research on resin-based dental materials will be included. A wide range of dental materials could be classified as being based on resin, thus in the scope of this study we will only consider the following types of resin-based materials: 1) adhesives, i.e., agents used to promote the bonding of resin-based materials to different surfaces; 2) restorative composites, which are materials with a polymer matrix highly filled by inorganic particles used for several purposes; and 3) luting agents, which also are composites but have a lower filler load and are used to provide the fixation between structures and surfaces.
To be included, the article should investigate one of these three dental materials and the main study outcome should concern that specific material. For example, studies classified as belonging to the ‘adhesives’ category should have been designed to evaluate the effect, influence, impact, behavior, and/or performance of one or more dental bonding agents, although the adhesive could be associated with other materials, for instance. In case the study aimed to evaluate an accessory material, e.g. a light-curing unit, the article will be included provided that the main outcome or response-variable is related to one of the eligible types of materials. In case the study cannot be clearly designated as a research on adhesive, restorative composite, or luting agent, the study will be excluded. The following materials are not eligible: glass ionomer cements, varnishes, silanes, products based on poly(methyl methacrylate), polymer-containing ceramics, and any other material that does not contain resin. Laboratory, animal, observational or interventional clinical studies, case reports, case series and reviews will be included, but opinions, letters, and editorials will be excluded.
Only papers in the field of dentistry, written in English, and published in 2019 will be considered. This year was selected because it was the last year before influence of the COVID-19 pandemic and, since the data is planned to be extracted in mid-2022, this will give at least 2.5 years for citations since publication of the article (MARX et al. 2001; PATSOPOULOS et al. 2005). A single year was selected to avoid further differences in citation timeframe that could be present if different years were included.
A structured search will be performed in the international scientific database Scopus (Elsevier, Amsterdam, Netherlands). This database was selected because it is comprehensive in terms of the number of dental journals indexed as well as because of the quantity of information about citations and other metrics it can provide. The search strategy will be based on specific terms using the keywords shown in Table 1. The search in Scopus will be refined limiting the results to: year (2019), subject area (dentistry), document type (article), publication stage (final), source type (journal), and language (English).