Background The aim of this study was to assess the severity of apical root resorption of tooth roots after orthodontic treatment with aligners. An attempt was made to compare resorption of tooth roots after aligner and conventional fixed appliances treatment and to determine the relationship between the duration of treatment and the degree of resorption. The influence of orthodontic forces on the occurrence of root resorption was also assessed. Material and methods The PubMed database, GoogleScholar and Access Medicine, Dentistry and Oral Sciences Source, Scopus, and Web of Science were used for the study using the keywords: apical root resorption, resorption, aligners, orthodontic resorption. Mainly retrospective studies, meta - analyses and systematic reviews were analysed. A total number of 20 literature items were used. Results Root resorption is evident after treatment with aligners, but most studies indicate that it is less advanced than after treatment with fixed braces. According to different authors, it averages from 0.25mm to 2.5mm. Shorter aligner treatment and intermittent forces on the teeth appear to reduce the degree of resorption. Conclusion Analysed suggest that the degree of root resorption occurring after aligner treatment is low. Although the review included a significant number of studies or in comparison to fixed appliance treatment further prospective studies are needed. It will be important perform study to observe malocclusions of similar severity treated with aligners and fixed appliances considering all stages of treatment.