The purpose of this systematic literature analysis is to review the application features of various types of acids and to determine the most effective etching technique to achieve maximum elimination of the smear layer. Materials and methods: the analysis of up-to-date Russian and English literature was carried out in Google Scholar and PubMed electronic databases. The analysis identified the features of various etching techniques using phosphoric, maleic and polyacrylic acids to achieve maximum elimination of the smear layer. Results: during the analysis, 67 articles were examined. After analyzing the literature on the inclusion criteria, the total number of publications amounted 31. Conclusion: smear layer should be removed using phosphoric or maleic acids according types of tissues: phosphoric acid application used on the enamel, maleic acid is applied on the dentine due to ensure a high-quality adhesive protocol, taking into account the sparing effect on the structural and functional units of tissues. Recommended exposure: applied to the enamel for 15-30 seconds, taking into consideration the type and the molecular weight of the acid. The exposure time of acid on dentin is recommended from 10-15 seconds, but an increase in the exposure time of maleic acid on dentin did not lead to negative changes in the structure of dentin, which significantly distinguishes the use of orthophosphoric acid. Also, static batching is not enough for high-quality treatment, because, in case of static etching, only the internal areas consisting of enamel prisms can be fully etched. Consequently, the use of dynamic etching is recommended. All authors contributed equally to the writing of the article. © 2022, Yerevan State Medical University. All rights reserved.