[Evolution and effectiveness of seventh and eighth generation adhesive systems in direct restorations. a review].

Introduction: : Dental adhesion is responsible for the chemical processes of dentin-enamel union for a correct choice before its application in restorative treatments; it is important to know properly the generation to which it belongs, its properties, application techniques, etc. All this is to ensure success in the procedures to be performed. Currently, adhesive systems have evolved, and 8 generations are available in the market, each with a better-quality standard than the previous one.

Objective: To identify which generation of the adhesive system is the most viable to be applied in direct dental restorative treatments.

Materials and methods: We reviewed and compiled 133 articles published from 20 years ago to date. After analyzing them according to their clinical relevance, 88 were excluded, the remaining articles were reanalyzed, of which only those focused on describing the generations of adhesive systems applied in direct restorations were selected, leaving a total of 56 articles, which included clinical case reports. The Google Scholar search engine, SciELO and databases of interest, such as PubMed, Scopus and Medigraphic, were used, three reviewers independently performed the analysis and search of data, and the keywords were used; adhesive systems, generations of adhesive systems, evolution, and direct restorations.

Results: : 56 articles were evaluated, according to their relationship with the subject and with the information previously sought, it was determined that the seventh generation of adhesive systems is the most viable to be applied in dental treatments, due to the improvements it presents in its characteristics, and the results with good prognosis mentioned by both dental professionals, as in research.

Conclusion: The advancement of technology implies new knowledge; therefore, the effectiveness of adhesive systems has changed significantly. Scientific evidence has shown that seventh-generation adhesives are more effective in direct restorations.