Background: The study of the patient’s quality of life is an important condition for assessing the effectiveness of the treatment and the clinical condition of patients after treatment, in addition to objective diagnostic methods. The purpose of the study was to investigate the dynamics of changes in the quality of life of dental patients suffering from caries of the contact areas of the lateral group of teeth, after treatment in accordance with the established plan for the use of various matrix systems, in the study groups. Material and methods: The study involved 147 patients: 48 patients of the 1st experimental group; 54 patients of the 2nd experimental group; 45 patients of the 3rd experimental group. Results: In the course of the study, it turned out that such a criterion as the quality of life is an informative dynamic indicator, the value of which depends on the method of treatment used. Conclusions: In the course of the study, the effectiveness of the use of a separation-retaining device for the restoration of the lateral group of teeth during the treatment of caries in the contact areas of the teeth was assessed as a factor influencing the quality of life of patients.